Hmm. Do you use a wig cap? That may help as it doesn't look like you are wearing one..Get a nude colored one. It will make the dark hair color go away and look like skin under that part of the har..Honestly though, Yea I'd say get a new one that's lonfder..while wearing one that's longer, find out how long that area needs to be before cutting it. In face, when I said I had the same problem, THAT was the problem..I didn't see how long it needed to be to cover (my hair is only about 2 inches long now so I no longer have that problem until it finally gets long again..lol)
EDIT: Btw, the front looks really good though..It's only behind the ears..When you get your pic taken, chances are no one will see that area unless it's almost a profile view.