Such a difference
I'm not really an art specialist, but in my opinion the wall seems to be done so much better than the potato. The wall is really great, in fact, it looks more like a wall than the wall of my house. The potato looks a bit too smooth, it would look more like a potato if you made it look a bit uglier, and with a bit more detail.
The eyes of the potato look nice though. A bit silly.
Last, the lighting. It looks good if you look at the shading around the potato, but on and directly behind the potato there isn't any shading at all. I at least expected some differences in his hair colour. Though you don't need too much shading, since the light shines on the front of his head.