The item’s thumbnail if it is readily available.
- iOS 13.0+
- macOS 10.4–10.15Deprecated
- Mac Catalyst 13.0–13.0Deprecated
If a thumbnail is not readily available, accessing this property requests it from the device.
When the thumbnail is received,
cameraDevice:didReceiveThumbnailForItem: is called on the the device’s
Execution of the delegate callback occurs on the main thread.