From the Namm and Messe demos we know, that there will be more machines.
Also the software for the processors used in Elektron machines is developed on normal computers (probably with special developer kits). Basically that allows the developers to output the display of the machine directly to the screen of the PC. So making screenshots of the actual OS is trivial, no need for photoshop.
So what you seen in the manual is a real screenshot from an unreleased development version of the Rytm’s OS.