Determining whether an LED module should use a constant current or constant voltage driver
In that unit, the description implies that the necessary series resistance to control current through the LEDs is included "on-board," and that the PCB is "wired" to be connected with others in parallel "daisy-chain" circuits.

With the option of adding more modules in parallel, a constant-current supply would only function properly with a fixed number of modules (i.e. a supply meant for 3 would burn up 2, or fail to properly light 4).
However, a constant voltage supply will properly light any number of parallel units, up to the number which will draw more current than your supply can provide.

The "available" constant-current PSU-driven version most likely has a series connection to "daisy chain" modules, and could be made without the series resistance that's necessary in a constant-voltage driven unit.