I'm using Playdate Mirror 1.0.0 (397958) from the SDK 2.0.3 on macOS 13.6 (22G120)
I've noticed that when mirror is not zoomed in (the default setting), it only displays a 399×239 screen image, missing the top row and left column.
This happens both on a retina and non-retina screens.
It might be showing half a pixel at 1x on a retina screen, the blur makes it hard to distinguish.
When zooming in to 2x or higher, the whole screen is displayed.
Thank you! I've started porting Mini vMac to see how it would run, still figuring out how to make it faster. I've just posted a thread about it too: Mini vMac – Macintosh Plus emulator
Will says the problem has disappeared after we fixed a related antialiasing issue. Look for it in the next update, and let us know if it isn't working as expected!