Help:) What does his body language mean?

Myabe the checking out (or so it seems) could have been he may never have really noticed and mya have noticed something nice and appealing about you, or maybe (not being funny) you had something on your face or you hair was out of place, but mily a women would look at you for that reason. It may have just been a man instinct to look at an attractive woman wether they have any intentions. As for saying thank you he may have thought you wanted to use the copier and he thought he was taking too long and was say thank you as in for waiting for me. And then it may have been genuine ist manners to open the door for you, and people in general don't really say your welcome that much as sometimes it sounds rude and saracstic or he may not have realised you said Thank You. As it was only two encounters it may not mean anything just that he's polite but if it continues to happen and he's saying things (like thank you when you didn't do anything) it may be to get your attention. ;) See what continues to happen :D Hope I helped.