Can't tell if that is a tub or a shower you have. If a tub, then get rid of the shower door and go to a curtain. If its a shower then go to a clear door. Both will help expand the room. A lot depends on what you want to spend too. Don't be fooled you can spend lots of $ on a small bathroom. Its also possible to reposition fixtures/door etc and /or steel space from adjoining closets to make small spaces more functional. For this you would need to find a bathroom designer in your area.