Uses of the artbook

Is it possible to use a screenshot of the artbook that i bought on steam for a private/non commercial use? I ask that beacause i would like to have a phone cover with one of those stunning pictures, but the seller tells me that it is under license.

You are not profiting from it, so it is ok?

Effectively, I even pay for it…

The seller of the phonecase would profit from it therefor he/she can´t make it
At best he/she could sell you a blank case and materials to do it yourself

So, which one of you two must I thrust?

Or even better, have someone the email of the artist that did the art book, so I can hask him/her directly?

I was an SH dev, but I don’t work at Riot anymore. The concept art was made by @Allie, but the legal rights are almost certainly with Riot Games, who have no official support channels for SH. Sorry I can’t give you anything more useful.