Star Trek Lower Decks: Every Easter Egg & Hidden Reference From 'Second Contact'
9. The Bunks
...Still more touring of the USS Cerritos has Boimler and Mariner showing Tendi the hallway where the junior officers apparently sleep, which features more of the previously mentioned LCARS-style decor.
According to Boimler, this hallway is located near the strangely musty sonic showers. Sonic showers were first introduced in Star Trek: The Motion Picture and were depicted in operation, scrubbing down B'Elanna Torres with sound waves or something in Star Trek: Voyager's "Juggernaut".
We've seen junior officers' accommodations before in TNG and Voyager, as well as bunks in Star Trek VI: The Undiscovered Country, but this is the first depiction of this kind of sad, communal living for Starfleet underlings. Boimler tells Tendi that as they advance in rank, they'll get their own rooms, but this arrangement really brings into question the whole utopian society and its hierarchical structure. But let's just leave it there.