@Peanutweeter breaks a rule of cool
One of the rules of cool is that coolness is not additive. If you take one thing that’s cool and add another thing that’s cool to it, it doesn’t get more cool.
@Peanutweeter takes that rule, and pulverizes it into the floor. Take a randomly awesome tweet (which is cool) and add it to a bizarrely appropriate Peanuts panel (and Peanuts is, and will always be, cool), and the end result is something that is rules-breakingly even greater than the sum of its parts.