What was the reason why data id was added to this code?

Code: https://jsfiddle.net/xhc73jug/

data.id Removed: https://jsfiddle.net/xhc73jug/1/

I think I got it!!!

For when using only a single video, and not multiple.

Code: https://jsfiddle.net/nj7vc1tw/2/