Er, "was Enterprise"? No, it was Enterprise that presented a new explanation (and it was not in the Mirror Episodes. What does their realistic-or-not nature have to do with anything? It is neither related to the actual subject matter, nor to the diversion I must apologise to Hendryk for having caused), but it was DS9 that established that TOS-era Klingons had smooth foreheads in-universe.was enterprise, "A Mirror darkle, I&II"...ive always found the mirrorverse more interesting, cos its more realistic in the originas of a human dominated society in space