You're too far away. When photographing art, here are some tips.

Set the canvas on the ground; prop it up against the wall, which frees up your hands, but it also keeps the image straight. Never submit a crooked image. Find a place either side-lit or back-lit; so you don't have any shine on the piece. The lighting in these is not bad. Try to include as much of the art in the photo as possible, but try to keep everything else out. Don't zoom and crop the photo afterward as a fix, otherwise, the image can be degraded. Just start with a better photo.

This artwork is crooked, but it's also only a small portion of the photo. It's hard to see because it's like the photo was taken from across the room.