More than one day later, a minute ago (at last), I realized m does not stand for metric measurement, but mile.
The larger red line makes suddenly sense !.
Now, reader, you know. If the situation arise, remember to think to your overseas customers and use mile instead of m.
Same will apply for temperature (F/C) and certainly many other measures (btw: 110 v in the USA, 220 v or 240 v elsewhere, 50 or 60 Hz for the alternative current).
For screen width, 13" is certainly know be developers, but what about standard customers ? Try 33 cm (33.02 cm) instead.
Update: I reread your message and saw, on a more careful read, that you already had figured out the correct explanation
I suspect in this case that the “m” stands for miles and not meters! as a mile is about 1.6 km, the scaling in your screen grab looks about right. In English, in general, we tend to use “mi” as the abbreviation for miles (or just write out miles as it is short enough). Which map service gave you this result?
I followed a subject on TV about how the Concorde plane was… created and build:
It was a joint effort done by two countries (U.K and France) using two languages, and two different system measurements.
They take the best from both group, became friends very fast and while in different countries and cultures worked as a team of friends.
The result is… the plane still looks futuristic and was drawn in the 60s (yes 60 years ago).
Delta wings, Eagle looking at up and down to/from the Airports. Using original ideas that goes to cars/trucks (titanium brakes) and slowly goes to other planes (never lost good experiences).
These people are adaptable people.
Some others stay glued in the old time, refusing to think (on some domains, not all) nowadays technologies or way of thinking.
The worst (really ?) are the ones who say the Earth is plane (a.k.a. not a globe) and the universe moves around the Earth. I do not enter with the ones who believes the Earth is x0.000 years old.
