I think it is impossible for Empress Xiao to be inconspicuous in appearance. After all, a woman who becomes a queen, unless she becomes a queen because of her great power, how can she be inconspicuous in appearance? But Empress Xiao has nothing Power, so this influence can be ruled out, then we can infer that Queen Xiao is really beautiful.
As for why the portraits of Empress Dowager Xiao that have been handed down now are not very beautiful. This is because these portraits are all circulated among the people. Because of her stance, many people don’t like her, so they treat her badly. The portrait of Queen Mother Xiao has been vilified, but if you examine history, you will find that the appearance of Empress Dowager Xiao is actually very beautiful in some historical records.
Why does Empress Dowager Xiao have 6 husbands, all of whom are emperors? This can be said to be a tragedy. Queen Mother Xiao was born well and married Yang Guang when she was less than 10 years old. Everyone knows that Yang Guang was later murdered by Yu Wenhua and was forced to become Yu Wenhua's concubine. But Yu Wenhua was also a short-lived ghost. He was defeated by Dou Jiande not long after, and Queen Xiao became his woman.
So from these two points alone, Queen Mother Xiao’s appearance is not bad, otherwise why would so many people keep her and not kill her. Not long after she stayed with Dou Jiande, Queen Mother Xiao was rescued by her sister-in-law and came to Turks. The Tian Khan of Turks fell in love with her, so Queen Xiao's fourth husband was the emperor again. The Turkic Heavenly Khan was old, and he favored women even at such an old age, so he left soon. According to the Turkic regulations, Queen Mother Xiao became the wife of the next Heavenly Khan.
Later the Tang Dynasty was established, the Tang Dynasty fought a war with the Turks, and the Turks were defeated miserably. Empress Dowager Xiao was taken back to the Tang Dynasty. I don’t know why, but Li Shimin took a fancy to her again and took her in. Arriving in his harem. In this way, Queen Mother Xiao successfully became the woman of six emperors, which can be called a legend.