In contrast to humans, the KQ5 sensor has been developed not to get a brain freeze even if it is in constant contact with ice :-) as you can see in the Cinemaxx Hamburg.
The KQ5xxx sensor is slimmer than KQ6xxx and has no pushbuttons.
The sensor is often glued to surfaces as it is very light and thin, offering sufficient adhesive surface. This is also so with this ice slush machine.
Here it looks as if the sensor detects the ice so that it does not overflow. This machine probably refills itself and the sensor ensures that there is always enough ice for the people in the cinema.
In other words, as soon as the sensor detects ice the machine stops its ice production. If the ice is below the sensor, the machine restarts its ice production.