It's definitely not just referenced, it's been traced.
I'm a little disappointed as I really liked the image and it feels a little less special now, which I don't know, maybe that's weird.
I also commissioned them for another image and now I'm worried that one has just been traced too.
The price I paid was fairly low so that's not really an issue but they are charging a lot more for their work now and I'm worried people will be paying those kind of prices for traced work.
I'm still looking around and have found something that might have also been traced but to be honest the pose is super generic so it's hard to say, going to keep poking around to see what I can find but in the meantime does anyone have any advice on what I should do?
[EDIT] I've now found another commission that was also definitely traced. Looking through the site the two photos come from (it's a Japanese pay site btw) there seem to be a lot of things that could match up but as of yet those are the only two I can definitively say have been traced.
I didn't want to do a full AB if it was a one off and even if I could prove a personal piece had been traced I still wasn't sure that was enough but now there really isn't any other option is there?