Hi!
That looks a lot to me as though he's listening, possibly for mice, maybe a stray cat outside. My boy does this when I let him in the garage, and he's very patient
I am with Rubysmama, that looks like bug watching or waiting to me. If they have seen something once, they can be persistent and be on watch for days and days.
You are all correct about the pushing of the forehead, and I am happy to say that none of his body touches the wall. I am believing he is just waiting for something to happen and being a cat. ( I am also happy to report that this past cricket season I did not had any crickets in side due to my hunters.)