The difference, by the numbers
They have no ingredient in common: the Corpse Reviver #2 has gin, triple sec, Lillet Blanc, lemon juice and absinthe, the Division Bell mezcal, Aperol, Maraschino liqueur and lime juice. In parts, a Corpse Reviver #2 is 1 gin, 1 triple sec, 1 Lillet and 1 lemon; a Division Bell is 2 mezcal, 1½ Aperol, 1 Maraschino and 1½ lime. By volume, the Corpse Reviver #2 is 25% liqueur, 25% spirit, 25% citrus and 25% fortified wine and bitter; the Division Bell is 33% spirit, 25% citrus, 25% fortified wine and bitter and 17% liqueur. Different bottles, similar balance: that makes them close cousins on the ratio map.
The Corpse Reviver #2 is the stronger drink in the glass (14.9% ABV against 13.8%) and holds more alcohol (1.67 standard drinks against 1.12). The Corpse Reviver #2 has more calories (about 211 against 150) and more sugar (11.0 g against 8.9 g). Both are shaken and served in a coupe.