The Invisible Patch

There's a spot in the living room where a sunken electrical outlet six feet up on the wall needed to be covered with a piece of drywall and patched with joint compound. My dad says its one of those places that you can see the difference in the wall if you know where to look. I know where to look and I still can't find it. Can you? I really don't know what we would have done without my dad's painting (and prep) expertise. All that's left in the living room is the trim, which he's going to return to finish. Good news, since we're kind of scared to attempt painting after seeing how well he did it.