Characters
How many times do I have to tell you? You don't put a bra in a dryer! It warps!
— Hedwig

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker repeats a warning about putting a bra in the dryer and ends with an emphatic explanation that it warps. The opening question suggests the instruction has already been given. The comic force lies in the irritation, with a laundry rule delivered as an exasperated scolding.
Context reviewed