Hey there!
I agree with Sophie, I think both can work. For us, because there's two of us, it's just easier with our little "logo"/talk bubble (which ties in with our shop name and theme). I think a (good) picture of the artist is personable and nice when the shop is doing well.
At this point in our shop's life, we've only made about 30 sales, so I don't feel like people would care what we look like. I just think for us (I think it's different for each shop), we are able to convey the personal but professional touches in other ways, rather than through our one profile picture.
Kathrine, you've got some really cool items! My one suggestion would be to concentrate on your pictures, especially since your items are so visual. I have been trying to concentrate on bettering my pictures and I've been playing around with PhotoFuze. However, I don't think PhotoFuze would work in your case. For your pieces, I think photographing them in a soft, natural light would really do them justice and make the colors pop even more! :)
Hope this was helpful!