There was a small sample at the very end of the scene-setting comic (to the humans it was advertised as a fireworks festival, but to youkai it was more like a challenge), showing off the format.
Spell card name and screenshot
Comment from the card owner elaborating on its good qualities
Evaluation by 5 of 6 judges (Reimu, Marisa, Sakuya, Youmu, Sanae, Sumireko) and an overall score
(Reimu is brutal as always, Sumireko is easily impressed, Marisa seems to focus on technical skill, Sanae and to some extent Sakuya value aesthetics, and Youmu is...Youmu)
Seems like they're playing off the popularity of the cross-reviews, but it should be pretty entertaining and more than just a Grimoire of Marisa II (even if it might not go as in-depth).