In the top picture, Drake is rejecting “Normal Summer Camp Activities” because most summer camps have fun things like swimming, games, and crafts. In the bottom picture, Drake approves “Shovel workout program” because in Holes, the boys at Camp Green Lake don’t actually do fun camp activities they spend all day digging holes in the hot sun as punishment. The joke is that Camp Green Lake calls itself a camp, but instead of fun, it’s basically forced labor with shovels.

In Holes, you have to dig 5 feet deep, and 5 feet wide holes everyday under the hot blazing sun. And when the characters finished digging the holes they are relieved after digging the holes, but when Mr Sir ( one of the counselors ) come and tell you that your hole isn’t deep enough, so you still have to dig more when you wanted to have a break off.