Humour is subjective. Like everything else in the world.
I think these two images are funny. Maybe just to me. I did actually smile when I was taking these and I was aware there was some sort of play associated with these images at the time.
At the very least these images are absurd. Funny or absurd they both touch on a common thematic. The incursion of man into nature and the reciprocal idea of natures incursion into man’s domain, the city.