Hi axpoo,
Both fit well. In the first sentence, "полюбоваться" means "to admire for a short period of time". In the second one, "admire" is seen as a long process. They are both correct.
"Paintings" are "картины", not "картинки".
Best,
Yulia Amlinskaya.
Russian Language Teacher,
www.russificateschool.com.