The difference, by the numbers
They have no ingredient in common: the Cinderella has orange juice, pineapple juice, lemon juice, grenadine and soda water, the Michelada lime juice, Worcestershire sauce, hot sauce, beer and salt. In parts, a Cinderella is 2¾ orange, 2 pineapple, 1 lemon and 2¾ soda; a Michelada is 1 lime and 6 beer. By volume, the Cinderella is 86% mixer and juice and 12% citrus; the Michelada is 86% mixer and juice and 14% citrus. Different bottles, similar balance: that makes them close cousins on the ratio map.
The Michelada is the stronger drink in the glass (3.8% ABV against 0.0%) and holds more alcohol (0.99 standard drinks against 0.00). The Michelada has more calories (about 171 against 76), but the Cinderella has more sugar (13.6 g against 1.1 g). Both are served in a highball; the Cinderella is shaken, the Michelada built.