Example validation issue:- uc06_audio_with_3d.json

[glenrobson]

Currently the Audio in 3D has a Spot Audio source defined as:

{
              "id": "https://example.org/iiif/audio/3",
              "type": "SpotAudio",
              "source": {
                "id": "https://example.org/iiif/assets/orchestra_tuba_10s.mp3",
                "type": "Audio",
                "format": "audio/mp3",
                "duration": 10.0
              },
              "angle": 45.0,
              "volume": {
                "id": "https://example.org/iiif/quantity/3",
                "type": "Quantity",
                "unit": "relative",
                "quantityValue": 0.3
              },
              "lookAt": "https://example.org/iiif/scene1"
            },

but the lookAt property says:

"The value of the property is either a PointSelector, a WktSelector, the URI of an Annotation which paints something into the current Scene, or a Specific Resource with a selector identifying a point or region in an arbitrary Container."

From https://preview.iiif.io/api/prezi-4/presentation/4.0/model/#lookAt

Is it OK to lookAt a Scene and if not where should this SpotAudio be looking?