What kind of job is this?

Here's another unusual job. We are making synth covers. There's a performance and it will be videotaped at a local school. The young children play synthesizers, so we are making covers so you can't see underneath them. Makes it look more professional. These took a while to figure out. Our mom taught us to miter, but she was thinking from the quilter's end working out. These needed to work in. A little different. So we had to make some changes.