Bon Bon made a very convincing argument for how good her bonbons were, implementing the most important parts of any sales pitch - volume, enthusiasm, stating that something is the best and somewhat fuzzy logic that made sense just so long as you didn't think about it too much. Still, it paid to be cautious, and Yona leaned in to inspect the offered treats, going through the motions of at least pretending to be sceptical, squinting her eyes and giving them a sniff. After handing over her last few bits to the salespony, Yona gobbled up the bonbon with such rapidity that any onlooker might wonder whether the yak actually managed to taste the treat at all.
"This..." she paused, herding her thoughts and judgement on the bonbon together, "...good treat. Even though Yona like treats ponies make, this treat is good."
The young yak couldn't quite bring herself to describe it as the best treat, but at least she'd spent enough time around ponies to at least understand that there was a state between best and, well, everything else. Like good. Just as she was about to opine further on what it was, exactly, that didn't make it the best treat, Yona's attention was caught by Princess Twilight and her praise on the volume of her cheering. The little smile on her face from eating the bonbon grew into a wide, happy smile, matching the sense of pride she'd felt at her cheering being acknowledged as great. Which was almost like best.
"Yona is cheering for," again, there was a pause, as she couldn't spot a single yak in the race to cheer for, and school pride meant that she ought to be cheering for someone from the school, but then there was the problem of there being multiple ponies from the school participating. Choosing one over the other wouldn't be right. When Wind Walker offered a suggestion, Yona latched on to the idea and ran with it.
"Cheering for Fire Walker! Fire Walker is, um, Fire Walker is," Yona leaned down a little closer to Wind Walker, though her eyes were fixed on Princess Twilight, her voice going down to something approaching a whisper, "which one Fire Walker? Just so Yona can cheer even better for sister-pony."