Subjects of Equestria! We are pleased to kick off the Nightmare Night Festivities and the 14th anniversary of the return of our beloved Princess Luna! Join us in celebration!
The collab rules don’t explicitly say anything about how tall flying ponies should be, but at around 520 pixels (head to hoof) I think this pony might not be tall enough. For sitting/standing ponies, rules 4 suggests at least 800 pixels. The empty padding around the pony does not count.
I’m also assuming you have a permission to use a flying character (see collab rule 10).