This picture implies that creatures exists in Equestria that look like tennis balld with wings. This also implies that what they put on Izzy’s horn was not a tennis ball, but a magical creature they believe can detain magic.
I wonder how many realize this is a transposition from the anime “Fighbird” (one of my favorite, by the way).
Basically, in that scene the main character, Katori Yutaro (aka Fighbird) is examining various life forms and calling them the wrong names (then again, Yutaro is actually an alien energy lifeform inhabiting an android, so he gets some leeway)
I was thinking the same thing