That's sometimes my sticking point too, though for different reasons. I don't feel that having my model emulate a pose I saw somewhere else can even begin to approach "stealing" the idea. There's no way to pose a person that hasn't already been done by someone somewhere.
However, poses that work well for one model certainly don't work for all models. So copying something that I like that someone else has done, doesn't always work.
I'm still getting the hang of studying a model's features and determining how to pose them to make them look good. Sometimes you see an image that just has that "something," but I can't always identify it (and therefore, create it) yet. Still a lot of trial-and-error for me, more than I'm really comfortable with, especially when I'm using someone else's time.