[MortalMonday]

That lithograph was damaged when he received it from treehouse. He put in for a replacement and treehouse agreed to replace it for him. Before replacing it, however, treehouse ordered him to destroy the original, damaged litho.

The guy obviously cut the number out to qualify it as being destroyed.

Treehouse probably instructed him to specifically cut the number out because they replaced it with another litho with the same number. This way, they can be sure that there are no identical numbers.