This is another one of our very regular daily visitors, shot in bright morning sunlight @10:15am yesterday. We have taken many shots of the more typical Nuthatch poses, but this one struck me as a little different somehow.
Great pose, nice background. Generally quite sharp, might do some selective sharpening around the eye.
For my taste, the bird is a bit big in the frame, might be tempted for a slightly looser crop. The other comment has to do with your favorite perch. It is an interesting one, but perhaps a bit heavy for the smaller birds. The fact that he is partly in front of it, does tend to reduce its mass a bit, as do the darker, shadowed areas.