I messaged AdultWork asking about Erobella and if there's a vulnerability in their system that allows for the Private Gallery to be downloaded and posted elsewhere.
(I doubt Erobella is paying for the gallery and then posting the images.)
AdultWork's reply is quite interesting:
Thank you for reaching us.
Please note that there is no such vulnerability and this is simply an affiliated site.
You can refer to the article below:
What are Affiliate Promotion Pages?
Erobella is a AdultWork's affilliate.
I remember checking a box that says I don't allow external advertising (or something along this line).
Erobella didn't post my Private Gallery photos but if they did, I would be livid.