My understanding is that heat is indeed removed from water to produce ice. Maybe "water is being frozen" would be clearer than "water freezes".
Freezing is to happen at -10°C because pressure is high (and with water, liquid is denser than solid, so pressure favours the liquid). But I didn't check if -10°C do correspond to 1500 atm.
There again, "supercooled" is misleading, as it suggests (to me) an unstable state. This water must be quite normal.
So it all looks like the normal freezing process of water by some chilling machine, except that it happens at -10°C because of the pressure.
Could that be it?