I have a file labeled TO BE FINISHED, and it encompasses all of time. My time, anyway. This is an old pun reworked into a possible t-shirt design. Along the way a few things changed. In the original it’s clear that the man is shaking the table. It’s clear because the other scientist says, “Keep shaking. I think we’ve discovered something.” To simplify the design I dropped the speech balloon, and went straight to the punchline.
So if you’re inclined to play cartoonist:
Should I put the speech balloon back in? Or does the cartoon work as it is? Is it clear that the plate is moving because of the disheveled scientist shaking the table?
Mark Heath cartoons 
I didn’t know the brownie plate had moved until I read the blurb…. so I guess I’d vote to restore the speech balloon.
Thanks, Claudio. I think you’re right.
I agree, I thought the larger scientist was eyeing off the Brownie to eat it.
Don’t add the speech balloon. Just put some motion marks around the table to show that it is moving. I agree with Claudio about not noticing the motion until I had read the caption, but I think the balloon might clutter the design. A couple of squiggly parentheses around the table would accomplish the same thing.