Greetings!  Since it is comforting to you, the dog is probably picking up signals from you.  Dogs communicate through pictures as well as cues from their owners.  I don't believe that this is a domination thing.  Dominant dogs do several things.  If they are sitting, they tend to sit kitty cornered with their paw on your foot.  They tend to lead rather than follow.  Your dog may also be having issues with separation anxiety as well which is adding to the behavioral mix.  If it is not bothering you and the dog doesn't seem distressed in any way, I wouldn't worry about it.