https://bugs.winehq.org/show_bug.cgi?id=34348
--- Comment #36 from Aaron Plattner aplattner@nvidia.com --- Unlike older systems, when RandR 1.2 refers to a "mode", it's referring to the actual timings being sent to the monitor. For Wine's purposes, those are largely irrelevant (aside from the refresh rate) since all that really matters to the applications running inside are the height and width of the framebuffer. RandR 1.2 has a transform mechanism that allows applications to scale an arbitrary region of the framebuffer to fill the screen, so Wine can make up whatever list of resolutions it wants and scale them to the display's native resolution. For example, if an application requests an 800x600 screen size, then rather than relying on sending actual 800x600 timings to the monitor, you can just scale an 800x600 desktop to the display's native resolution.
The point is that RandR 1.2 puts this control into the hands of X clients like Wine. What they choose to do with it is up to them.