Stills from @s.nemz’s example videoWhy does the sponge matter?
The sponge first looks like a useless way to pay. The last shot gives it a job. The prop ties the reveal to the kitchen ending, while the character’s composure sells the joke.
Which clip is the reference?
The linked TikTok post by @boby.biggsjohnson is the version traced for this guide. Look for the bill, the sponge and the walk toward the kitchen. The linked post establishes a reference version; the earliest upload is unverified.