Installing sensor dimmer to replace bathroom light switch beside fan switch
I can’t tell but I think I see a bare copper middle right or possibly a green screw , this is the proper grounding point.  It looks to me that each switch has a black wire that goes to the same wire nut this would usually be the hot because if the hot was on the top of the left switch when you turn that off the other switch would not work. My guess is the fan has a separate conductor run for the light , prior to remote controls it was common to run 2 circuits to a fan 1 for the fan 1 for the lights so either or both could be on or off.