Why do people treat me differently when i tower over them? (Working in a food truck, they have to look up at me)

Hi, i’m wondering if their is a name or theory or research on this. Google isn’t helping but i may not be wording it right.

I was working a couple of shifts in a food truck at night time, serving food to people. I was kind of anxious as most of the customers were drunk people (worked at a bar and it was horrible, drunk people can be unhinged) but at the food truck this is never an issue. If someone is rude or people start bickering or fighting in the queue it is much easier to get them to behave or listen to you or be nice than it was at the bar. Basicly they are much more submissive and easier to handle than when i worked at the bar. Other thing i’m noticing is i’m getting hit on more than i have ever been in my life on these shifts. Girls are complimenting my eyes, voice, hair, asking for my socials or when i get of my shift and etc.

The only common denominator i can think of is that in the food truck i’m literally towering over the people while leaning out of the window to serve them or talk to them. They have to look up at me to communicate. Their heads are where my waist is so as i say i’m towering over them. Is this an affect that has a name? Or has any theories or research on? That people treat you differently and respond in such ways. Generally just curious as i’m being treated a lot different on these shift than in any other situations by people and customers.