From V0.6 firmware, there is an extra entry in the Menu accessed from the Mode Button.
Test mode is only available if V0.6 was factory programmed, it does not appear where V0.6 was installed via LaserCube web admin page OTA update.
If test mode is selected, via holding down the Mode Button for 2 seconds whilst the Test Mode menu item is being projected, the LaserCube will project one of a series of test patterns.
The pattern may be cycled by a short press on the Mode Button.
There is now way to exit the test mode, other than turning the LaserCube off, then back on again.