I found a photo which to my eyes shows that the design at the pendant section of the necklace is a swan - so I'll dub it the swan necklace.

The photo is from the same occasion as the video



Detail





The necklace appears to have jewelled sections which may act as sliders to shorten the necklace or perhaps they are just to add interest to the chain section.



This is a very unusual, individualistic piece of jewellery, which I suspect would not be easy to wear.

I was very surprised to see it was a swan as like J-F I thought I saw a butterfly - but obviously it was the sparkle of the diamonds which created that impression in the video.