Social distance refers to the space between people for which no precise scale of measurement has been devised. It's the space between the waiter and the waited upon, measured not in inches but in fractions of dignity. Let's say that dignity can be measured with reference to everyday signs of acknowledgement - eye contact, subtle nods  either in agreement or disagreement, smiles and other evidence of recognition. Blowing my caappi, I realise that this canteen is different. Some kind of shrinkage has taken place as the skilled masseuse and the cleaner sit at the table next to mine enjoying their late morning break. I see the overlap in the Venn diagram of difference and inequality, an intersection in the sets sealed by a burst of laugher. 

Then, I think of the indignity of silence. 

The cold absence of eye contact. 

The enforced isolation of degraded life worlds, when bodies are invisiblised through sheer force of will.

It I don't see it, it doesn't exist - sounds like some kind of shared pathology in perception.

The hierarchy of work ensures that some people are only semi-present, as they don elaborate camouflages to erase their footprints.  This is the ultimate magic trick: labour without labourers, buildings without builders. Cleanliness without cleaners. Only sharp eyesight can detect the ghostly figures, the muted shadows that melt into the background, retreat into cubicled  spaces violently separated from those who enjoy the full benefits of being human.