> I could only imagine it in a place that only serves tourists and foreigners.

Maybe not "only", but yes, they're typically Americanized brunch places, or other "trendy" places. And some of those places have good food worth eating.

It's still a pretty rare thing, fortunately. Something less offensive that I'm running into more often is to be asked if we want to leave a tip. And more common still are PoS systems that give you the option on checkout.

Probably not the thread to digress into what's happening to dining in Lisbon (eg the rameniffication of everything) but it's definitely bringing in a more tip-forward mindset.