As for its operation: it's an attachment that fits to an existing door and uses motors to open it in a new way. The device is designed to have multiple input mechanisms, such as auditory (hand claps), light, or vibration (taps), and run on basic AA battery technology. In an industrial setting it could be keyed to RFID or other mechanisms to work as the mechanical assist to open/close a door with larger power and design optimization.
As for who would want it, there is a 'basic' version intended for senior citizens and pet owners, up to a 'connected' variant which can have all sorts of activation programming conditions. Essentially if one wants a door to open by itself, as though a ghost was doing it for them, this is the mechanism for that convenience.