If you watch the video of this, Trump keeps emphasizing “Door Dash Granny’s” (on her shirt) husband needs cancer treatment. That could be scripted or she could be a real Dasher that got paid some (probably very small) payoff to do this. Either way it’s just a photo op where he tries to play up how his Big Bill throws pennies at poor people by not taxing tips (which from what I’ve heard have often been stolen not just by restaurant managers/owners but even through apps in some cases).