If I'm not mistaken, that looks to be taken on her Orlando vacation, back when she was around 5k, give or take. She had a few videos on Youtube exploring the hotel and Disney Springs. I think this was at a time when she was first starting to feel boobie greed and unsure of just how large she wanted her boobs to be as she kept moving the goalposts. When you consider that Foxy traveled to Belgium to get regular 2000cc implants, but decided on expanders when they were offered for the same price, and what has happened since, you get the real life sense of the boobie greed that expanders offer. Maybe just a little more becomes I need another fill as your breast size becomes increasingly less manageable, you still want to make your boobs bigger. The bigger they get, the more beautiful you feel, and who would fault someone for wanting to feel good about themselves?
If Foxy could find 20k shells, I believe she would love to fill them. Of course, at that size, she will need to find someone to help her with a variety of everyday tasks, but I have to assume that would not be difficult.