user
Given a cartoon image and a caption. Caption: I didn't get it at first either, then it hits you. Question: Generating an explanation of why this image/caption combination is funny. Answer: 
assistant
A play on words. Modern art is hard to understand at first but a revelation about the meaning of the work could figuratively "hit you" after some time. But here, the deer are literally "hit" by a vehicle on a highway, where they would be standing if they were looking at these signs outside of the gallery.