Returns all the current presence sessions for a space. Presence can be associated to a User or a device resource. If the presence belongs to a specific user, that user model will be embedded in the response. If it belongs to a device, likewise it will be embedded in the response.
Presence reporting by a device is indicative of "anonymous" presence where it is not known who is in the space, just that it is occupied. This information is inferred from device data from a sensor, such as an infrared sensor.