Title text: [title-text similarly alphabetized]
An epigram is a brief, interesting, usually memorable and sometimes surprising or satirical statement. Constrained writing is an age-old literary phenomenon, where writers impose rules or patterns in their works. (Haiku is a well known example.)
Just in case you have been living under a rock for the last several years, Twitter is a short message social network / communication service. All messages (known as tweets) on the service need to be under 140 characters, including private messages.
All the words spoken by Megan, from "Yeah" to "alphabetization", are in reverse alphabetical order. It both answers Cueball's question and exemplifies with an ingenious self-reference, while being short enough to be a valid tweet — hence the "whoa"...
The title text, "title-text similarly alphabetized", is also backwards-alphabetized and self-referential.
[A man sits at his computer desk, motioning toward the screen as a woman stands behind him.]
Man: I don't get why authors and comedians spend so much energy trying to be clever on Twitter. Couldn't they put that creativity into more books and scripts? -- Is there something they like about the 140-character format?
[Same picture, only the man has his arm down.]
Woman: Yeah. Writers working under tight restrictions produce novel material -- like, for example, epigrams employing backward alphabetization.
[The man remains at his computer desk. The woman is no longer in the frame.]
Man: ...whoa.add a comment! ⋅ refresh comments!