Complaining vs telling it as it is

What is the difference between complaining and just telling it as it is, i.e. noticing something negative in an objective and neutral way?

The words "objective and neutral" seem to be the answer. Then one is not too involved, stuck in the feeling of being upset with the negative thing.

Complaining makes us focus on the negative and be personally invested into the feeling of blaming and being pissed off.