I'm guilty of saying "I wish I could pull that off," and it's always coming from a place of admiration, and yes, envy. It usually has something to do with dressing a body type that does not play well with looks that I really admire -- styles that look great on a straighter, slimmer type than mine. It's never, ever intended as a slam against the other person, but I admit, it's coming from a place of insecurity about my own appearance. I hope no one has ever thought I was doing anything other than showing my own weakness.
That said, I was relieved to see the second link -- that is the only one of those things I've ever said to another woman! But a lot of them have been said to me! LOL