He was trying to let you know he was being honest in telling you you were attractive by letting you know his view was realistic, not idealistic. It was an awkward attempt to demonstrate sincerity in the compliment by being clear that he wasn't overstating the case. Understandably you took the not a pin-up part as a slight and have focused on that rather than the compliment he gave you in telling you you're attractive. It's the sort of thing people do sometimes to try and make clear that they're aren't just telling another what they want to hear. I don't know your history with him and previous comments about this sort of thing--your appearence--and what self-esteem issues you ahve about that issue, but in an attempt to appear sincere he spoiled the positive feedback he gave you. He wanted to compliment honestly without you taking it as an overcompliment--i.e., not believeable. He made a real mess.