All in all, this has lead to a lot of discussions amongst He-Man/She-Ra fans about the nature and appearance of Horde Prime. Here is my interpretation:
If Horde Prime was the leader of the Horde, then why was Hordak’s face on the emblem of the Horde?
And this is what got my geeky little brain rolling. The basic assumption that I make in my illustration is this: it is not Hordak’s face on the Horde emblem. For my version, the armor was based on the UK comic book version, while the hand was based on the cartoon depiction. His head and face are, of course, based on the Horde symbol (or by retro-continuity, the basis for the Horde Symbol). As for the secondary head, I just wanted to give him his extra head in an unexpected way. Oh, and I assume that Horde Prime is, like Hordak, a shapeshifter, so the secondary head can retract and morph back into an eyeball. I view Horde Prime as Hordak’s brother, who started out roughly-human sized like Hordak–over time, his shapeshifting abilities developed further, and eventually he was able to use his powers to increase his size.
For more on Horde Prime: