With all the technological clutter Tony has in his workshop you can be excused for missing something that is so small that it's barely noticeable at all. Lots of stuff that Tony does in there we just don't understand, we simply take his genius for granted and don't question his methods. But what we all understand is that a coffee mug must be the right way up if its full of coffee. As Stark sits at his desk working on the design for his Mark II suit, he reaches for his mug and takes a sip. His facial expression suggests that whatever is in the mug has gone cold due to the length of time he has been sat at his computer, though what is even more disturbing is that a second earlier the mug can clearly be seen upside down on his desk. Either he invented a mug that flips itself upright and fills itself with coffee, or thats a pretty bad continuity error.