These are details photos of a stud mounted sign panel.
The pattern is taped to the sign or wall where the graphics go.
Then holes are drilled through the pattern and into the wall, indicated by the cross hatch as shown. The studs are then secured in the holes by silicone or epoxy.
Dimensional clear anodized metal letters, mounted on MDO (industry plywood) with stud mounts and spacers. The board was painted to match the surrounding trim.