What I find humorous about them is that the human being relates to something in her/his surroundings in a way that is either unexpected or imitative- and it's presented visually in such a way that it makes me think/laugh/wonder about it in a way that I never would if the person weren't placed and posed in exactly the way he/she is. All the elements come together perfectly for me in these. Love his work!
It is not easy to make pictures that are humorous. I can count on the fingers of one hand the photographers who have made me laugh out loud when looking at their work. Elliot Erwitt has done it with single images, while Duane Michals has done it using multiple images in a series. German photographer Ivo Mayr does it, too, and in a fresh and exciting way.