Bar icons sit level with their neighbors
A change merged into quattro draws the bar glyphs with distance fields so the workspace square's top row stays level, and it measures the outline before scaling the icon back down.
David Heinemeier Hansson reported that the active workspace's rounded square had a top edge that stepped up at its right end, and that it sat about a device pixel above the icons beside it. The square had been painted at 10.8px instead of 12px.
In the live bar its center moved from 25.23 to 26.00 device pixels, in line with the icons beside it, Hansson reported. Every bar icon picks up the same correction.