On Tuesday, Quentin Tarantino added his handprints and footprints on the sidewalk outside Grauman's Chinese Theatre in Hollywood, and he left a small surprise with the footprints. Apparently, Tarantino was wearing replicas of the shoes Uma Thurman's character wore in Kill Bill. This matters greatly for his footprints, because the shoes have a hidden Easter egg:

The shoes have the message "f**k u" on their soles. And that's exactly what was left behind in the wet cement with Tarantino's footprints:

Sources: TMZ | Dulce Osuna | Twitter