she is wearing a diaper. She clearly noticed it by the fact that her legs are cold, and that something thick is under her. Suddenly, her computer turned on, and showed a video.
"Hello Heather! You might of notice it by now, but you are wearing a diaper. Well, we here at Pampers needs a tester for our new adult diaper project, Dri-Hi. Luckily, we saw you through the TV, so we wanted to test you. Now, as our new test dummy, you will that exact diaper for an entire year, without taking it off once. The straps has a lock deep within your skin, so unless you'll tear your skin off, you are stuck in them. Of course, we'll give $10,000, and 5 years worth of the project if interested. May your day be good. Good bye."
Heather is now scared and happy all at once. She has to wear this diaper, unless she literally physically herself. But she gets to feel her baby self, and she gets 10k at the end, with the 5 years worth of those diapers.