That would be at the front of Citadel of Spring. A segment at the front of the ship sticks out about a hundred meters from the rest, and it's exposed sides and ceiling are covered in windows. The room isn't a bridge (the ship control rooms are well-defended near the ship's center, seeing outwards only with cameras and sensors) but it does function as the place where most fleet-wide speeches are given from as well as the location where the legendaries lead the fleet in major religious ceremonies.
Easily visible within the space is an elaborate abstract mosaic taking up most of the floor space, 150 meters wide and thrice that deep into the ship. The ceiling rises 70 meters to meet the roofs of the greenhouses which line the interior of the cylinder. The interior walls before the windows begin are covered in gilded bas relief murals and multiple levels of balconies. A section at the very front is raised as a stage, and permanent cameras and spotlights point towards it.
The room isn't especially full, though there are some people filing in to look out of the windows. One woman in her 60's stands on the stage beside a very large daemon, dressed in a blue and white gown. A few others in similarly elaborate clothing are making their way to the front. The woman waves towards her.