Panel 1: Elly smiles as the man that she asked for directions looks at her class schedule and says "This is a coincidence...I'll teaching the class you're in."
Panel 2: As she and her prof walk down the corridor, he tells her that she'll find this a most challenging program.
Panel 3: Her smile broadens after he tells her that many of his evening students are preparing for a serious career.
Panel 4: As he disappears into the crowd, he tells her "Others just want to write for their own enjoyment."; this causes her to deflate and stare the Bug-Eyed Glare of Existential Horror.
Summary: Since Professor Horgenstank originally wrote Elly off as a bored housewife, his "condemning" her as simply wanting to write to please herself is meant by Lynn to have mutated him into a different sort of condescending jackhole. This is because she seems to have not noticed that his parting comment is neutral and only exists as a slam because Elly thinks it is.