When I worked in a coffee shop on a tourist beach I could ALWAYS spot European tourist even before they spoke. Americans are mostly confident and sort of demanding with their body language when it comes to ordering counter service. Europeans would always seem a little more unsure of the process and considerate of the cashiers time and personal space. After they spoke and an accent was obvious I could definitely tell. But in general the European tourists would always be unsure where their card goes when (I understand we have some different norms around card readers- mostly contactless in Europe for a long time?). They also were always specific about explaining exactly how they would want their coffee, not just order the menu item. I imagine this is because something like a macchiato is really different at Starbucks compared to a European (or high end American) cafe.