Inner voice and mindfulness are keys perhaps to an external shell or armor for such social dismal behavior.
Curious how you would see the correct way to as permission to pay what the person "may" feel is a compliment?
Had a friend with image issues and a "normal" compliment set them off, as it was always negative to them.
We do not know the story of people we meet in the world for the first time, what level of assumption is appropriate? the knowledge of the environment and situation is not always available to adjust, do we miss out on great interactions as we are too afraid to engage?
Sorry going off the plot a little.