When I say espresso or "bica" as it is known in my country this is what I mean
A very strong usually short shot of coffee with a 2mm layer of creamy foam. These small cups are usually filled to 2/3 for a normal espresso and 1/2 for a short one.
The care cafe shops go through to ensure their espresso is the best is quite extensive.
Usually the cups, sugar packets, grinder, espresso machine and coffee is supplied by the manufacturer. There is normally a contract for the supply and maintenance.
There is a very fine tuning of both the grinder and the espresso machine to produce a good quality espresso and this is done at least once a month being the top quality places services every week.
Make no mistake, if the quality is not very good customers will walk away to the cafe next door. It is normal to have 3 or 4 cafes together in healthy competition so we do have plenty choice.
Lastly espresso in Portugal is like facebook and Instagram, is the reason for people to get together. This for work, leisure or family gathering.