Multiple realities(covers information from several alternate timelines)
The Emmette-type was a type of starship operated on Earth and by Terran Empire before the NX-class of starships.
The SS Emmette was a starship in use on Earth and Luna before the NX-class of starships. (Star Trek: Enterprise title sequence)
A ship of this type in the mirror universe assaulted the Lunar colonies with photonic torpedoes. (Opening credits, ENT: "In a Mirror, Darkly", "In a Mirror, Darkly, Part II")
This type of starship still used Rocket like nozzles on the aft end of the ship. (Opening credits, Star Trek: Enterprise; Opening credits, ENT: "In a Mirror, Darkly", "In a Mirror, Darkly, Part II")
Ships of this type
Seen only in the opening credits, this model would inspire the "Warp Delta" starships seen in both the prime and mirror universes.