The “comma” mark at the center of the ventral hindwing is slimmer than the Eastern Comma’s and it resembles a capitol “L”. Eastern Commas have a bolder and more rounded mark very similar to an upper-case “C”. The underside wings of Gray Commas definitely have gray tones vs the Eastern Comma which is mottled purple and brown or tan. There is also a really cool greenish and black squiggly line along the ventral edges of the wings (more prominently so on the forewing), which is distinct.