I’ve been using a late 2012 i7 Mac Mini as a headless server running Plex and other services for a few years. I noticed certain resolutions would be unavailable when I remote connected to it via OS X screen sharing and portions of the screen would often just appear black unless I dragged a window over them. Reading up on this issue it appears that if nothing is plugged into the Mini DisplayPort or the HDMI port the Mini does not load the OS X graphics drivers that allow for acceleration of the GUI and prohibits all available resolutions from displaying. This does not appear to be a problem solely relegated to Macs as others on Amazon reviews and across forum threads have commented on similar lackluster performance using their NUCs and other headless servers. I purchased the Compulab 4K Display Emulator and it has immediately solved these two problems. I’ll also say that I had success using Display Menu to switch to a higher resolution before purchasing the hardware dongle. The downside of using Display Menu was that the computer natively booted to 640 x 480 and the File Menu would go black when I switched the resolution to 1920 x 1080. Thanks to the 4K adapter pictured above I no longer have to adjust the resolution after boot up and I don’t get any graphics anomalies. Below is a screenshot of all available resolutions available with the dongle and Display Menu installed, the Mac Mini now natively boots to 1920 x 1080.
