Just some things that I would like to mention - my personal opintions(!):

Preview screenshot:
Almost perfect ;) A little deeper fingers/fist view, like at your #16 vid would be perfect! Think about it - it's the first thing users will see, and the vid is about fisting, not just fingering, you might hook some more fans hehe.

Video preview:
It's great, and does not spoil too much :D

Camera shots:
A great close up side view on your ass. Your face is out of view most of the time though, it would be great to have your face and expressions in view too, while you play with your ass like that :)

General performance:
Half of the vid is about sensual and slow strip down panties and ass fingering and getting ready for fisting (see the preview hehe). Which is damn sexy, no doubt, but some longer fisting time would have been great, compared to the intro/getting ready.

Lingerie/Outfit:
I like black/grey stuff more :P

Final words:
Overall great video quality, lighting and action, lots of ass play (including that special ass play) and some sexy dirty talking too. It is a good thing that you lied about it, girls who do ass fisting are rare to find! Please keep practicing (I hope I'm not alone with this wish hehe). Ass fisting needs a lot of practice, and it is so hot to watch girls do it.

thx
ceph