I flipped the image simply to check for issues. In older times, artists used to look at their paintings in mirrors in order to spot mistakes. It helps to see the painting with fresh eyes again so that you can spot mistakes. Like in my painting here, I didn't notice that his brow and eyes were wonky until I flipped the image. When you look at something one way for a long time, you sort of just start to ignore mistakes likes that because you get used to them.
Thanks for the comment/question!
RE: Dwarf Portrait