I don't know how accurately I managed to depict it, but you could say that this is a little "fast forward", symbolized with the black boxes indicating a little timeskip. So while they encounter more random weirdness, they actually got quite a bit closer to the dreaded mirror room! Yay! :'D

Also, this accumulation of strange findings doesn't depict daily school life very well. It's usually only half as weird.

The boys continue on their path and happen upon more weirdness, like a random snake that hangs from the handrail and hisses at Kei...

Kei: "SNAKE!?"
Taku: "It's just Kuroda-senpai's electronic pet snake."

...or a big hole with burn marks in the wall...

Kei: "And... what happened here...?"
Taku: "This must be the place where Kishida-senpai got in a fight and blew up the wall."
Kei: "..."

...or a huge painted heart that was smeared on the wall to deliver the message "Please go out with me, Mayumi-chan!!"

Kei: "Who did this...!?"
Taku: "Probably Sagara-senpai, who's not-so-secretly in love with this Mayumi."
Kei: "..."