@Tetrominon  
Thinking about this too much, if the magic system is LaundryVerse-style, that’s a stored procedure activated by an immediate command with quite a lot of extra implicit permissions and syntactic sugar. “Try it and see” = “Attend, thou! Inline and immediately try current procedure forever, redo once necessary conditions are observed!”
 
Quite a safe way of doing it really, although it does depend on a reasonably intelligent bound entity. Majesty is quite the accomplished computational daemonologist! Obviously Old Ponochian Command Dialect™ requires rhyming like other programming languages require semicolons…
 
@Phantom Rider  
Unless they’re wished into existence, or drawn into existence, or found under some river ice or something.

@when she felt her wings unfold  
There’s another story where a human refers to humans as “mortals.” I forget which.
 
Of course, with the mirror, they’re all technically a series of clones.

@when she felt her wings unfold  
Nor birds, apparently.

So, Turnip Top works quite like the Stone Angels. That’s not horrifying at all.
 
Also it’s quite heavily implied that ponies aren’t strictly speaking mortals.