Background Pony #AA5B
I'm not sure where this alleged context regarding Celestia and betrayal is coming from. The description in the source clearly says this is nothing more than practice on emotional expression (and the artist further goes on to respond to a commenter stating that this isn't based on any episode). I get that people like to form their own headcanons about what's going on in contextless pics like these, but should we really be tagging based on assumptions rather than what the image actually objectively depicts?