From Gineipaedia, the Legend of Galactic Heroes wiki
Imperial warships are typically large and ornate compared to Alliance warships. Typically built following particular social agendas, the upper decks were spacious and elegant for the officers (and the lower decks cramped and dingy).
Imperial bridges were constructed like throne rooms. A set of stairs lead up to a raised central dais upon which a captain or fleet commander may sit. Staff officers and advisers would stand to either side of the captain's chair, or sit on couches behind the chair. Bridge staff were located in sunken trenches surrounding the dais. Officers consulting the ship or fleet commander personally would have to stand at the base of the dais' staircase, giving the appearance of supplicants appealing to a noble or monarch. The bridge ceiling is dome-shaped, and covered in screens displaying the stars as seen from the surface of the ship. Officers' quarters are accessible via recessed stairway directly behind the captain's chair, or via tunnels on sides of or behind the central dais. Captains wishing to rest or obtain a view of the stars could recline their chairs. Bridges seemed to be located towards the dorsal surface of the hull, but did not emerge from the surface of the ship, unlike the tower-like bridges of Alliance ships.
Imperial ships typically followed a vaguely wedge-shaped design, with a long, snub-nosed central hull, with a secondary hull emerging from the ventral surface. Located towards the rear were multiple drive thrusters arranged around the primary and secondary hulls. The port and starboard surfaces of the typical Imperial battleship often sported secondary hulls, which housed cannons, missile launchers and Valkyrie launch tunnels.
Though Imperial weapons technology was slightly more advanced than that of the Free Planets Alliance, Imperial shipbuilders chose to focus more on the aesthetics of each individual warship instead of solely prioritizing combat efficiency. This meant that Imperial warships were typically larger than there FPA counterparts, and possessed fewer weapons. On the battlefield, each ship class on one side was roughly equal in ability to the same ship class on the other.
Unlike Alliance ships, Imperial vessels are capable of atmospheric entry, and can deploy troops and vehicles directly via landing ramps and claw-like "feet" to effect contact with the ground.
Although all warships are painted in a uniformly gray color, the warships of the Imperial Fleet were much more varied than the FPA Fleet. So, for instance, the Black Lancer Fleet, led by Admiral Bittenfeld, were uniformly black, and many flagships were distinctly marked (the Brünhild is white; the Tristan has a blue stripe etc).