Girl crush refers to the admiration or adoration that one girl has for another girl. It could be to do with hair, body, make-up, car, clothes, career, talents etc.

Girl crush指一个女孩对另一个女孩的仰慕和喜爱之情，这种感情可能跟发型、身材、妆容、座驾、衣装、事业以及才华等有关。

A key element to the girl crush is arguably the appearance of the crushee, and yet the classic girl crush is decidedly nonsexual. They may just want to be the crushee’s best friend. (Source: urbandictionary.com)

女孩之间这种喜爱之情的关键因素可能是被喜爱那一方的外表，不过，标准的女孩喜爱之情绝对跟性无关，她们可能只是想跟自己欣赏的女孩子做好朋友而已。