Why did Minister Yu say Emperor's words were not a compliment towards FTY, Why the Emperor mockingly remarked FTY as being 'more filial than her father' & didn't send any gifts to the wedding venue, didn't even send any eunuch to congratulate ZL-FTY's wedding :

Bcz In the banquet of Grand Empress Dowager's birthday, FTY & ZL have offended him. & the whole banquet situation of upsetting the emperor was a clever play set by Diva Mrs. Yu by using Mrs. Wu.

The Emperor in the drama is based on Hongzhi Emperor of Ming Dynasty, Zhu Youcheng. Zhu Youcheng's father was Emperor Xianzong. By chance, a low ranking consort named Lady Ji was favored by Emperor Xianzong & became pregnant. At that time, Consort Wan held exclusive favor & power in the palace, & her supporters were eliminating all potential heirs to the throne. So Lady Ji dared not report about her pregnancy publicly and secretly gave birth to Zhu Youcheng.

Zhu Youcheng was raised in secret from a young age to avoid harm from Consort Wan. At the age of six, his identity was revealed, and he was made Crown Prince. However, soon after, his birth mother, Lady Ji, died suddenly, and the eunuch protecting him also perished. Crown Prince Zhu Youcheng's situation became extremely dangerous at this time, & His grandmother, Empress Dowager Zhou, took the 6-year-old Zhu Youcheng to Renshou Palace to raise him personally.

According to detailed historical records, Consort Wan once summoned the Crown Prince to a banquet, and Empress Dowager Zhou repeatedly instructed the child not to eat anything. The Crown Prince, wary of Consort Wan, said he was full when fed, and when given soup, directly asked if it was poisoned. He lived in hiding until he was six years old. Even after being made Crown prince, he walked on thin ice. If it weren't for his grandmother's protection, he would not have been able to stay safe for several years as the Crown Prince. Therefore, he had a deep relationship with his grandmother.

According to the "Veritable Records of Emperor Xianzong," ("宪宗实录"), When Emperor Xianzong was critically ill, he summoned Zhu Youcheng to his bedside & ordered him to ascend the throne as soon as possible, adviced him for "以敬天法祖, 勤政爱民" (Revering Heaven and honoring ancestors, governing diligently and cherishing the people)

In the drama, we see the plaque in the Palace that says "祖法天敬" ("Respect Heaven and Follow the Ancestors"), represents Emperor's filial piety, also mirror's his father's dying words "Respect Heaven and Follow the Ancestors".

Zhu Youcheng, after ascending to the throne, bestowed upon his father a full temple name & posthumous title, buried him in Maoling with complete rites. He did not purge Consort Wan & her family, nor did he posthumously depose or demote her. He also did not publicly criticize the shortcomings of his father, consistently maintaining his filial piety and respect for the late Emperor. But He did not grant a wish of his grandmother.

Zhu Youcheng honored his grandmother as the Holy, Compassionate, and Benevolent Empress Dowager and served her with all his heart. However, the Empress Dowager always had an unfulfilled wish- that after her death, she would be enshrined in the Imperial Ancestral Temple. However, according to the ancestral rules of the Ming Dynasty, only the emperor's first wife and empress could be enshrined in the Imperial Ancestral Temple. The Empress Dowager was originally a concubine of Emperor Yingzong of Ming, whose first wife was Empress Qian.

Throughout her life, the Empress Dowager fought hard for her own status (wanting to replace Empress Qian, the legitimate empress of Emperor Yingzong), but Emperor Zhu Youcheng insisted that he could not break the national etiquette for personal reasons and refused to budge.

Given the historical context mentioned above, returning to the drama, When Grand Empress Dowager is saying "As descendants, we shouldn’t only honor our parents, but grandparents as well" side eying the Emperor, She is showing her resentments towards this exact matter.

The Empress Dowager's words openly expressed the Emperor's lack of filial piety towards her. For an Emperor who proclaimed that he ruled the country with filial piety in mind, being publicly criticized by his grandmother was a humiliating. If we Look at the emperor's embarrassed expression, He's furious, his eyes are practically stabbing, but he still has to keep smiling.

The emperor could only vent his anger on Zhao Ling and his wife.

Mrs. Wu said that the Empress Dowager always remembered her great-grandmother's nurturing kindness, invited their whole family to celebrate every year. They thought it was a great favor, but it turned out that she only breastfed for 3 days! Inviting Mrs. Wu every year was actually a show for the Emperor, "For 3 generations This is being so grateful after just three days of breastfeeding? I've raised you with such care since you were six, a debt of gratitude from Heaven!"

Mrs. Yu naturally understood the intricacies of the situation, which is why she had Mrs. Wu go to the Grand Empress Dowager & seemingly casually mention that FTY wanted to move her grandmother's Tomb. Dowager immediately became interested in the matter of the tomb and decided to make a big deal out of it on her birthday.

The matter of moving the grandmother's grave became a widely publicized affair, which Madam Yu seized upon, easily causing them to offend the emperor without their knowledge.

Credit - https://m.weibo.cn/status/5334514268113253?jumpfrom=weibocom

Everyone knows Zhao Ling's backer is directly the Emperor, this is particularly why they have to move cautiously about doing something... In one of the previous episodes, Zhao Ling warned Tingyun stating any move He or she made would be over-interpreted in the upcoming days. We have already seen how Everything involving them becomes a matter of buzz & hype in the Capital, They had to keep a low profile about Fu family affairs, at least for a time being as 5th master Fu's publicized scheme had just ended after all kind of gossips. This was certainly not a perfect timing for her to move the tomb of Old Madam Fu, specially if they were aware of the Emperor Grandson-Grandma's deal, which Zhao ling might not be aware as he came From a humble background but i wonder if FTY also didn’t know About this matter? Mrs Yu said something reflecting upon this, "For family like ours, being well-informed is the most important thing."

& Emperor is already well aware of things that happened to our lead couple 7 years ago, including the fact that FTY was poisoned by her Grandma & their escape just afterwards, the very time when they first met, So He internally questions about her intentions for moving the tomb, is it really bcz she loved her grandma & wanted her to rest in peace or it's just a show off? Emperor had Every angles to doubt FTY's intentions bcz he clearly knows she wasn’t present when old madam died & surely didn't know if her wish was really to be buried in the ancestral home in Huaying as she claimed in the banquet. Emperor even decreed their marriage just before the topic was raised. FTY literally replied, "I just kept my Grandma's wish" which is the exact words that made him upset.

Also, It's not a big matter that Emperor didn't personally sent someone to the wedding venue as he already gave his gift of Jade Ruyi as a wedding gift in front of everyone while bestowing them Royal marriage decree. So It's not even a "venting of anger", It's just he was taken aback & was upset by her words giving dowager ways to criticize him, so he didn't have the mind to send an envoy to represent him joyfully in the occasion.