user
Given a cartoon image and a caption. Caption: You promised me you would stop after you lost your arm from that paper cut! Question: Generating an explanation of why this image/caption combination is funny. Answer: 
assistant
The person writing in the giant book only has one arm pictured, so it's plausible that the other one is lost: specifically, the joke is that this person really likes to write in a big book despite the fact that the giant pages caused a giant paper cut which caused the person's arm to entirely get cut off. This is much more damange than would be caused by a smaller paper cut from a smaller book. It's not clear why they are so intent on writing in this book, and their partner wishes they would stop before they lose their second arm.