The tags on Pixiv use "reddo" instead of "satoshi", and from BabelFish, it seems the artist may have opted for the silent hero rather than the vocal protagonist.

セキチクシティのサファリゾーンで再会して　ふたご島→グレン→マサラ→トキワまで同行してたという妄想　　　主人公はサトシじゃなくてレッドなので、カスミはアニコスしてるんです

So, commentary request?

Well, I don´t know about Red, but in HGSS Misty definitively shows some interest on him (she mentions him once or twice, I think), and even more in Pokemon Special manga