Don't worry guys. From what little experience I have from love 4komas mokou will show up in the nick of time and everybody would be happy...but this 4koma will then end....oh...
Every time I see the thumbnail of this image, even though I know what it is... for a fleeting moment I see the final panel as a cave in a mountainside in an old 8-bit game.
So seeing Marisa and Alice together reminds her of her position with Mokou, or lack thereof. ...That's an interesting take/plot on relationships in Gensokyo; reflection and the sort.