A lobby bar is an odd little civic space. Guests are waiting for rooms, locals are meeting friends, somebody is working too late, somebody else is ordering champagne at an hour that suggests excellent news.
It needs a reason to stay
The best lobby bars are not holding pens. They have their own visual logic, good seating and a menu designed for the ambiguity of hotel time: coffee at four, a martini at five, fries after a delayed flight, dessert because the night is not over.
Local energy matters
A room filled only with hotel guests can feel sealed off from the destination. When locals actually choose to meet there, the property gains a different kind of credibility. You begin to understand the city through who walks in.
There should be corners
Not every seat should perform the same social function. A great bar has the obvious center and the slightly hidden table, the solo stool, the sofa that can absorb a group. The architecture gives people permission to use the room differently.
We often judge a hotel by whether we would return to the bar without sleeping upstairs. When the answer is yes, the place usually understands hospitality beyond the room key.