Ok, I was a bit worried at first because the pillow wasn't expanding as much as I had hoped. But then I reached out to their customer service, and they informed me that it takes 24 hours at least for the pillow to gain its original size.
So I waited.
And waited.
And waited.
Somewhere around the 20 hour mark was when I began to see that it's actually expanding nicely.
Though it took more than 24 hours for it to fully expand, the wait was worth it. And I'm now using it every night.
So, if...