Pomona believed in letting people as well as plants to bloom in their own time. This might well be a sign he was finally loosening up a bit toward his co-workers. What a perfect motif.
So lovely! As a dumpy old lady myself, I really appreciated this fantasy for dumpy old ladies. It's a long, satisfying ride to the conclusion, and I'm glad you gave them some time to argue and have a spat, or it wouldn't be Snape.