What? Are you really saying you couldn’t tell if someone is from Spain or Russia? Germany or UK? Hair colour, eyes colour, skin colour, height, facial features are all completely different. Try finding blonde, 1.9m tall Spaniard with blue eyes for example. There are exceptions obviously, but 99% of the time you can easily spot a Brit/German/Polish/Russian in Spain. The same is true for Asia. I’m sure it’s very easy for them to tell Japanese/Chinese/Korans/Indians apart.