who spends her days selling canned memories while listening to the Puerto Ricans complain that it would be cheaper to fly to San Juan than to buy a pound of Bustelo coffee here, (9-12)
Even though they complain, don't you get the feeling that these Puerto Ricans are repeat customers? For starters, where else would they find Bustelo coffee? That's the kind of thing that allows them to connect with their homeland. And doing so allows them to connect with the store owner and each other, as well.
[…] Cubans perfecting their speech of a "glorious return" to Havana--where no one has been allowed to die and nothing to change until then; (13-15)
The Cubans are another community-within-a-community here. That they all have the same "speech" indicates that a big part of their sense of community is a shared focus on returning, one day, to their homes in Havana.
as they speak to her and each other of their dreams and their disillusions-- (22-23)
This isn't a case of TMI. The shared experience of being an expatriate in a foreign land is a powerful source of community, one that brings everyone closer together.