What I'm seeing on your picture is that the stripe goes all the way through the eye to the nose (which it doesn't on some of the other "fake" ones) and that the fins are clear. Ours also has those slightly golden highlights on either side of the black stripe on the tail.
Of course, anyone can be wrong. If you notice him/her being aggressive, it's not an SAE. Ours are very peaceful, and will occasionally play with other fish, but not in a way that is chasing them at all. Also with behaviour, SAEs tend to space out and lie on a rock for a while, just chillin.