2012-04-12
Explanation
This comic plays on the famous Rubin's vase optical illusion, in which negative space between two face profiles creates the shape of a vase. In the main panel, a man enthusiastically describes the illusion to a woman: "It's an image where you can't tell if it's two people looking at each other or a vase." The woman responds skeptically with "Riiiight..." The meta-joke is that the comic panel itself is drawn in exactly that style -- we see two people in profile facing each other, and the space between them could be interpreted as a vase shape. The man is unwittingly describing the very image he is part of.
The caption at the bottom reads "Fun fact: All blind people think we're idiots," adding another layer to the joke. Since blind people cannot see optical illusions, they would find it absurd that sighted people are fooled or fascinated by simple visual tricks like the face/vase ambiguity.
The votey panel shows a URL reference to Scribd.com with a link to "Amazing Optical Illusions," continuing the optical illusion theme as if the character is earnestly sharing a link to more of these illusions, oblivious to the irony.