Comics is a static medium. That means they don't move. And yet everyone wants them to move. That's why the more popular ones wind up in other media; because the real money lies in motion (cartoons, live action movies, and video games).
But the challenge of working in the comics medium is finding a way to overcome the reader's natural tendency to see static images as unmoving. Through panels and pacing, the artist's goal is to pull the reader's eyes across the page and create the illusion of movement and the passage of time.
Although simple, the comic above "moves": it takes you a few seconds to read the dialogue (so it takes place in time); and there is a change in the characters' positions between panel one and panel two (a motion you understand). Thus, a static image (two really) becomes a silly conversation between characters in the reader's experience.
That's the idea anyway. It's not always successful. But it's a completely different mindset from moving media.