I had a pickax and a sword on my Fury Warrior, and I wanted to have two pickaxes. But when I went to transmog it, I was unable to make my sword look like my pickax (counts as an ax). I assumed this was because the sword is a sword and the pickax is an ax. But, just to test it, I tried to transmog the pickax to look like the sword, and I was able to.
Why is it like this?
Both of them were two handed weapons and both were soulbound.