Also people barely ever just draw whatever a random internet person ask for, unless they advertise they’re doing request, even then, they will strongly lean towards actual friends and people they know. You’re not breaking a rule, just saying. As a background pony you don’t even have an identity, the artist might not even get any exposure or credit, or even a genuine reaction, unlike if they drew for someone they actually know, like their friends.
The trick to get a random artist you don’t know to draw for you, is being willing to pay for it, preferably upfront. Artist don’t want you randomly friending them, and start info dumping about what you want or are into.