What would you add to this workshop nook before calling it done?

A vise would be my first pick if you expect to clamp or hold pieces often. You could mount it on a separate board and clamp or bolt that to the bench when needed, which keeps your options open while you figure out how you use the space.

Before adding much weight, check how steady the bench feels when it’s on its wheels. If it moves or racks, consider bracing it first. For storage, a simple shelf between the lower supports is easy to add and keeps things visible. Shallow drawers are possible too, but I’d make sure they won’t get in the way.

Lighting and power are the upgrades you’ll notice every time you work. A movable task light can help with close work, and accessible outlets are handy if the layout allows them. I’d also plan where dust collection or a shop vacuum will go, rather than letting hoses and cords become an afterthought.

I’d keep the extras tied to the projects you actually plan to do. A first-aid kit and fire extinguisher are useful basics, then add storage, a vise, or dust control as a real need shows up. No need to cram every workshop idea into a small nook at once.