In src/controls/GlobalDrawer.qml#n215, the width of the GlobalDrawer is set to Math.min (Units.gridUnit * 20, root.parent.width * 0.8) Units.gridUnit * 20 works out to 260 pixels on the desktop. That's really wide for a minimum width. Why not just use the content width? Because Discover uses the GlobalDrawer as an always-visible sidebar, it's comically wide and generates user complaints. See Bug 385992.
Not needed, and I was misreading the code anyway (confused min() and max() ). This width is probably fine when it's used for its intended purpose.