tape0.0s
columns0
slit2px
The wordmark is already crossing the slit. Try the bird, then slow the tape down.
The Camera
The source lives on the left of the frame; the slit sits at the gold line. Every column that passes the slit is copied onto the tape and the tape shuffles left, so a still object makes a flat band and a moving one makes a slope. Space hold the tape, C clear it, S save it, 1–4 switch source.