R, 108 minutes. Through today only at United Westerly.

A droll, easygoing procession of slights, obstacles and microaggressions on the road to an artist’s gallery opening, “Showing Up” could be classified as co-writer and director Kelly Reichardt’s first comedy since her “Old Joy” 17 years ago. But labels are deceptive. There’s subterranean seriousness underneath the deadpan-comic surface here, and much of Reichardt’s previous work found plenty of quiet comedy and seemingly accidental lightness amid some pretty tough lives. This one’s a portrait of low-level frustration, endured and finally, slightly dispelled.