What do you mean by a prince on horseback or a Tang priest?

It is said that the man riding a white horse is not necessarily a prince, but a Tang priest.

This is just a joke on the Internet. Hehe, this is popular now, which means that people often say Prince Charming, so this is Prince Charming. Then, this Tang Priest rode a white horse when he went to learn the scriptures, so it may be Tang Priest.