All YouTube videos now have a circle in the top-left corner when in full-screen mode and the UI is active. This circle seems to be solely links to a channel of a company paying for the placement.
Seems to be brand new form of ads for YT
https://www.reddit.com/r/youtube/comments/6atymk/weird_icon_at_the_top_left_corner_of_a_full/
Seems to be brand new form of ads for YT
https://www.reddit.com/r/youtube/comments/6atymk/weird_icon_at_the_top_left_corner_of_a_full/
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