The framed item is a sign for Sinclair Aircraft, a real company that goes
back to the early days of flying (we got permission to use it).
C&C is military shorthand for Command and Control, which is the function
of the Observation Dome (sometimes thus referred to as Babylon Control).
There are hand-holds built into the seats, and on the walls and railings.
>From that angle, unfortunately, you can't see them holding on, though you will
be able to see it in "Survivors" and "Chrysalis," among others.