This taqueria's outdoor tables offered several flavors of nieve ($1.50) with the option of something extra: a chili-powdered cup and a liquid core of chamoy, a Mexican salty-sour-spicy-sweet sauce. I don't know how well the lemon, melon, or pineapple nieves would take to this treatment; mine was jicama, which provided a nearly blank slate for a surprisingly refreshing treat.
The full formal name would seem to be jicama nieve chamoyada ($3), though you'll get fewer funny looks if you ask for a chamoy or a diablito. Do note that those shorter names also apply to concoctions made with ice. Almost without exception, streetside operations will feature an ice-crushing or ice-shaving device, or tubs of nieve, but not both; take your pick.
4711 Fifth Ave. (47th-48th Sts.), Sunset Park, Brooklyn