Hold Confirm

a delete button you hold. the ink spreads from your finger and the button swells, then the bin's lid flies off, spins and lands back on it.

key insight: the fill is one number that holding adds to at a constant rate and letting go drains on an exponential. it measures time honestly, and a press during the drain catches it where it is.

the ink is a red copy of the button clipped to a pill that grows from the press, so the label turns white exactly at its edge.