It seems to me that one aspect of "poverty mentality" is a refusal to go outside of "the rules" even when doing so would clearly be within the socially acceptable gray area. I'm not talking about someone with privilege selfishly believing that the rules don't apply to them. I mean minor things like putting up a lost cat flier without a permit, ducking into a random restaurant and asking if they have napkins to clean up a spill, or teaching a small yoga class in a public park without a permit. The fear seems to be that if those in authority are given any opportunity to crack down or refuse a request then they will do so.
What I have noticed is that it actually does seem like those in authority are more strict with them than they are for me (note that in this case I'm talking about people who are the same race and in some cases the same gender as me).
I've come to suspect that in addition to "poverty mindset", there may also be some sort of unconscious body language or other indicators that allow people to subconsciously pickup that someone comes from poverty. I don't have any proof of this, it's just something that I've suspected. So I don't know if there would be any value in trying to look at any of these potential cues?