When expanding or collapsing, QTreeView animates this creating a pixmap which is then animated. This pixmap does not respect the devicePixelRatio of the window the widget is in.

This leads to blurry text and sometimes even icons changing during the animation. This can be observed in eg. QtCreator's project tree or QDBusViewer.

Note how in the screenshow the text below the entry I expanded "plugin" is blurry and that the folder icon at the end of the list is different from the rest.