Go on, I dare you!
Oh sure . . . cover up your own inadequacies of knowledge with your banal memes and GIFs. They mean nothing to me. Hit me with your best worst.
It appears that the UI item contains the names of clips or sequences in the source or record panels.
It does not appear that you can select said clips or sequences.
It could be a ui element used to host a list or dictionary for some other purpose like sorting or prioritizing.
Or it could be the self-destruct button that I need.
On my end it is unreadable gobbldy-gook. I’ll do a screen shot tomorrow.
On further timewasting investigation 
it appears to be called the Sequences Handle
The Help Popup says:
“Click and drag to the Media panel to copy or move all open sequences to a section of the Media Panel.”
I tried, it didn’t.
(also, I can’t think why I would…)
If I click on the button it lists my sequences, and sometimes those sequence names are followed by “Operation Aborted” or something like that.
But this is boring as dirt.
I prefer the ejector seat.
Moving all Open Sequences to a New Reel or a New Folder
Those pesky flame developers - always writing documentation that I have to go off and read…
Ha. Mine doesn’t look like that.
Same for me. I never found it useful. Just a confused popup and a prohibited icon, wherever I’m trying to drag them. I’d prefer a popup sequence selector, to open a sequence selecting by title, in a clear way.