The Healing Brush and Clone tools are fine for fixing blemishes or removing certain things in an open area, but get near a hard edge and these tools become less useful. Realistically removing a large object takes careful attention to detail, and it’s just something Photoshop can’t quite automate.
Here is the finished “Matrix” effect:
A: You can still see little bits of the chair. You can see a hint of the chair’s tan color in a couple places down the side of the body. This is an easy fix. Zoom way in, to 700%, and just carefully erase them off of the top layer.
B: When cutting out the chair, we ruined the shadow in the photo, but we can fix this by making our own.
C: You can see some minor repeats in the grass, which makes it look less natural. Getting rid of them will complete the illusion.