This is an entrance to a “boutique shop” (even though we’re on the moon, this is still just a digital website and people gotta shop and create/consume entertainment). The way bases are built in this sci-fi world is, underground. (you can assume energy is cheap and almost free in this world.) But during excavation, the ground is dug up and put somewhere. There is a dirt hill the size of the base, next to each base. For this one, they made an observation tower out of this dirt. So there is a tall tower-looking structure made out of concrete-looking material. Next to it, is the entrance underground. A hermetic double-door. (Optionally you can draw a car entrance, although the pedestrian entrance suffices.)
Next to all of this is a BIG projection advertisement, the size of a bus. Projector refs are below. The way 3D projectors work, I think, is there are 4 projectors on the bottom of a stage, that project 4 intersecting light planes on top of the stage.