Into the Spider-Verse eliminated depth of field: nothing goes soft the way a camera lens makes it, because blur looks like a photograph and the film was meant to look printed. Comic pages are printed in passes, one colour plate at a time, and sometimes the plates land out of line. VFX supervisor Danny Dimian (Sony Pictures Imageworks): "We noticed that sometimes in printing comic books, the color offsets were not aligned properly and this looked like the image was out of focus." So they "splintered and offset the image in a way that is similar to a misprinted comic book page": the farther from focus, the farther apart the plates. Lead compositor Geeta Basantani: the same tool, fed motion vectors instead of depth, made "that really unique motion-trail look on things."

Our own street and our own cast; nothing from the film is shown.

Did you notice the city splitting before we told you?

Sources: Mike Seymour, "Why Spider-Verse has the most inventive visuals you'll see this year!", fxguide, 17 December 2018; Foundry, "How Sony Pictures Imageworks created the film's signature graphic look almost entirely in comp".
Sounds: our own, made in code (earshot, CC0).