英语高手请进,关于句子成分.

问题描述:

英语高手请进,关于句子成分.
he relished the thought of seeing her with her new dress on.
这句话中句尾部的"on" 我看不懂,能说明一下吗? 最好说个例子.

with her new dress on,这里on是穿着衣服,即她穿着新裙子,wearing her new dress
She's wearing a beautiful dress today.You look pretty on that new dress.