I can't open the pics up from thumbnail, so all I can see is both of you look about the same, and both in better shape than I could have been at half the age I am now, most likely. None of us will ever figure women out, but I can say that my wife says she likes the "teen boy look" on me, which isn't any easy task at age 43. Your GF might like the same, if she's saying she wants you to look more like Efron. Boys tend to have a little more body fat while still having definition... Vascularity and super-definition is more mature, which evidently isn't popular with the girls so much. My wife specifically doesn't like me to get big traps or a thick neck, and she would much rather I keep my defined sixpack than to get thicker chest/arms, and lose the definition. The good thing is that I don't want to be any bigger anyhow. But it's nearly impossible for me to keep what I have, and not also have a thicker neck and humped traps.
Back to your GF and you, I hope you have a STRONG, STABLE relationship with both of you wanting a long future together, if she's trying to tell you how to sculpt YOUR body. Nothing wrong with working in that direction, as long as you're in it together. There's nothing worse than a woman in a man's life, who makes him change everything about himself, only then to crap out on him. Been there/done that.
Charles