It removes the disguise and the associated personality hidden behind place, authority and social upper-hand. It diminishes identity with artificial supports for an ego. When ego is lessened, positional attitudes lessen. There is less confrontation, people tend to listen better.
When social place is gone with clothing it throws people off of their bad habits of judgement and projection. The cues are not there, so they need to look a bit deeper, before they see any stereotypes to project on to others. They often are more cautious and civil at first. When you get to know someone without the labels you see them with more respect, more as just another person. You yourself are stripped of identity and the associated behaviors. Still, in time, one finds ways to judge or just identify people into a group, with subtle clues, or not so subtle. It takes longer and they commonalities may by then override the conflicts.
Gender, can't be hidden, race, facial features body size are all prejudices recognized commonly and by law to be wrong reasons to discriminate. Discrimination is more often a negative value. My point being that we try not to discriminate and accept a book by its cover. The effect of nudity doesn't help change these other prejudices very much directly.
People tend to accept and perceive that most people are not playboy material when everyone is nude. That helps in acceptance. Acceptance promotes mutual respect. No one has to overcompensate when naked.
There is a tendency for people to drop off inhibition, relax and be more honest when nude. This is true and a basic support of nude encounter groups.
Experience in a naturist resort is commonly perceived as, "People are just more friendly there."