I saw this cartoon on Facebook, and thought there was a little something wrong with the wording of the dialog, or something like that.

Anybody else confused by this?
I made a comment, and got what I thought was a snarky reply. But that commenter added something about “not trying to be snarky” and actually explained something I hadn’t understood. (But that’s what we’re all about here, Not-Understanding Comics.)
(But in the comments discussing the content of the cartoon, Mr. Greenbar did come off as argumentative and rather, yes, snarky.)

Is this convention/technique something that people here know about?