I never did get it. Looks more like an elephant to me.
Should’ve been named “the Rohrschach Nebula.”
https://apod.nasa.gov/apod/astropix.html
My theory is that it was named that before astrophotography was as good as it is now. Today’s amateur photographic equipment is better than what was available to professional equipment a generation ago.
It really DID look like a horses’ head at one time…
(You can cue in the Don Corleone and Luca Brazzi jokes now)