>>7500157 (lb)
The same horizontal bar is at the bottom of the photo of POTUS's pen and watch used by Q in drop 3642 to confirm the tripcode.
Possibly because they're both iphone screen caps, they have exactly the same width/height ratio, which means that they can be overlaid.
I've taken the saturated parts of the skull image and overlaid them on the watch/pen image.
Maybe it's my imagination, but it looks to me like there's an alignment between the colored regions and the watch hands.
For example, the orangey color seems to line up with the long hand of the upper small clock, and the hour hand of the large clock points at a yellow square on the periphery of the watch.