everything
Explanation
This comic takes the concept of an "everything bagel" to its logical and absurd extreme. A customer asks what's on the everything bagel, and the vendor explains it has "everything -- literally everything, otherwise it'd be false advertising." The customer points out that there are other everything bagels, and the vendor explains that those are included too, "because by definition the everything bagel contains everything, including itself."
This is a riff on Russell's Paradox and self-referential set theory. If a set contains "everything," does it contain itself? The everything bagel becomes a mathematical paradox -- it must contain all other everything bagels, and those bagels must contain it in turn, leading to infinite recursion. The final panel shows the vendor appearing pleased with this logical catastrophe while the customer looks disturbed. The comic satirizes both the casual use of the word "everything" in food marketing and the mind-bending implications of naive set theory when taken literally.