i met this guy at the gym, he's awesome and we get along very well.
I was on checking out a few pictures of his and I realized that I look a lot like a girl who seems like his now ex. I then realized that the first time he spoke to me was the first time he saw me looking normal (ie non gyming look). I thought this was a bit strange since he'd seen me for about 2 months before hand as well but never said anything...
btw, he's still in contact with said ex-gf but as friends. what should I make of this?
What you describe is fairly normal, actually. We all tend to be attracted to certain physical traits. If you think about the guys you've liked, I'll bet you realize they shared some features.
Many of the girls I've dated have looked similar. Probably, he was attracted to you not because you look like his ex, but because you're a redhead with an oval face (or whatever you look like!) and so was his ex.
Most people date a certain type of person. You may have similar traits to his ex, because those traits are traits that he finds attractive in a woman.