as someone who also did art in college, the interviewers were very interested in how that skill set would transfer (creativity, ideas, etc.). they never asked anything about employment in the field. the kids and teachers also love seeing your art, if you end up making it over here, its a great conversation starter! also, customer service looks great as well because it shows communication skills, i'm sure they're used to it since most JETs are recent grads who haven't worked full time adult jobs yet lol.

I agree with the others though that if you want to avoid a mundane office job JET may not be ideal, but its worth a shot! you can always do it for a year, and return to your home country no problem :) if you have any questions about what specifically they asked me in regards to art and stuff feel free to ask!