This menu is for customizing the player's character. This requires several other systems, like shape keys, clothing and jobs.
The character appearance is the menu where the player decides the character's shape, mass, height, hair, skin color, special features and other things:
Character loadout is the menu where equipment like clothes, tools and cosmetics are assigned to the character:
Job selection screen is where the player sets their preferences for their role on the station:
The Server Lobby is the menu for the individual server after you have chosen to connect to one via the Server Hub. From here you can join the round (if in progress) or spectate it.
It also serves several other purposes:
Provides server information/images custom to each server.
Includes a lobby chat to talk in OOC with the other people in the server. (needs image)
Provides a list of players and possibly occupied roles.
Allows changing the game settings (video, audio, UI, etc.. as in #in-game-settings):
Allows editing/saving character presets at any point prior to embarking. (needs image)
Grants server settings to admins so they change aspects of the round and start/stop rounds. (needs image)