100% scale produced wrong physical dimensions onscreen
Showing a DIN A4 PDF file, e.g. https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf, at 100% scale in evince does not produce the document at the correct physical size (210 × 297 mm) on the screen. At least in my setup, the document is 3.5cm wider than regular DIN A4, i.e. it measures 24.5cm in width.
In comparison, Okular shows the correct physical dimensions at 100% scale.