Hello, I am the joke explainer. My job is to explain jokes to make sure everyone understands them. The joke here is that some of the people who visit or work at this office are annoying. JOKE EXPLAINED.
This picture is funny because the person who made the sign was clearly frustrated enough about this problem to make a sign about it. JOKE EXPLAINED.
What is funny about this sign is that the cost of a pizza is so much less than the cost of a house, making this reward paltry in comparison to the cost of the home. JOKE EXPLAINED.