Agreed that it's not worth changing, since it's clear enough as written.  But one idea for getting a little bit more efficiency is to do only 4 copies:
- Strip along left side
- Upper left and strip along top can be done together
- Lower left and strip along bottom can be done together
- Then upper right, strip along right, and lower right can all be done together.

It uses some of the copies that already happened, which are then contiguous for the later steps.  But like I said, I think it's probably fine as is unless we notice a speed bottleneck here and it becomes worth optimizing some.