玉树临风 means handsome, generally, it's not only good looking, but also tall and good shaped. This word is only used to describe man, NOT woman. 胜 means that someone or something is better than other one or other thing in general. 潘安 was a famous scholar in ancient China, he was a very handsome guy. So the whole sentence means "(someone) is more handsome than 潘安", it means the guy is really really handsome.

玉树临风or风度翩翩 is a Chinese idiom to describ a man who is dashing,handsome, chivalrous and personable. 胜 means “than”. 潘安 is one of the most handsome men t in Chinese history. 玉树临风胜潘安means a man who is more handsome than 潘安.

It means some man very handsome, remember, for male.

玉树临风 is a saying that describe a man who is handsome,潘安is a name of a handsome man in ancient times.胜in here means "better" or "winner". the whole sentence means someone is very handsome.