Why does annixter calls his story last cover?

A pet fox named "Bandit" grows up and leaves the house where he was raised from a kit by two young boys. He turns into a chicken thief and all the farmers in the countryside get together to hunt him down. The fox outsmarts them by hiding in a pond, his nose sticking out of the water so he can breathe. The youngest of the two brothers wanted to be an artist and used to make framed pictures out of old box covers, drawing the pictures after the frames were made. Having gone through the life changing experience of losing his beloved pet, who ws eventually killed, the drawing he made of his pet fox was the "last cover" he drew on before his childhood was over.