QFileDialog Mac / PC

[Brandybuck]

You can't set the starting directory on the Mac, because QFileDialog is using the native Mac dialog, which doesn't have this. Instead it uses the last directory seen. This is standard Mac behavior, and Mac users will expect it, so I wouldn't worry about it.

The image preview and info also comes from the native Mac dialog. Qt isn't doing this, OSX is doing it. To get this behavior on other platforms, you'll need to write your own file dialog, preview and info routines, etc.