When uploading an observation on the website, if you drag the observation to a blank area of the screen (i.e. not another observation) you get this pop-up (error message?).
Obviously dragging here is meaningless, but it seems like the pop-up should say something like “You just did something nonsensical.”
Dragging off the window doesn’t do this. Instead, the icon zooms back to where you dragged it from.
Happens on Chrome, Firefox, and Safari on Mac (which is all I tried).