So...Chitanda's reaction on the previous episode was just a surprised one, I thought that she remembered something again. Admit it...if this episode were made by a complacent studio, I’m guessing they would do a sloppy job like relying on different angles and close-ups 😏. This is but a speculation but seeing the quality of some anime nowadays proves my point. I predicted what Oreki did in combining the ideas, since it matches his character. A plausible answer has been made but it looks like it is missing something crucial 🤔