Looking for a Tokyo Metro poster with ‘Where’s Waldo’ style illustration had Tokyo cultural elements.

Hi everyone, I hope this is okay to post here, I'm a bit out of ideas and thought someone might be able to help.

I was recently in Tokyo on an education trip and regularly used Ryogoku Station (the Toei one, on the Oedo Line). On one of my last days there, I noticed a really cool poster as I was exiting the station. It had a very detailed, 'Where's Waldo' style illustration filled with Tokyo cultural elements, landmarks, people, various scenes all packed together. There was a QR code at the bottom, which I scanned with my phone at the time.

Unfortunately, I'm now back home and realized I didn't save the website or take a photo of the poster itself. I've tried searching through the https://www.kotsu.metro.tokyo.jp/ website but haven't had any luck finding it.

I know this is pretty vague, and I apologize for that. Does this ring any bells for anyone? I'd really appreciate even just being pointed in the right direction. Maybe the name of a campaign or what type of poster it might have been? I'll leave some images as reference.

Any help would be genuinely appreciated, thank you for reading!

https://preview.redd.it/3kqknqed0kig1.png?width=1000&format=png&auto=webp&s=fb016578ddf448c073b3f568ccc798b43088cb67

https://preview.redd.it/12phgl3qzjig1.png?width=1000&format=png&auto=webp&s=e98a5f7d0a3be908c55bc4f858b01787e1ef4e1b

by Material_Display_726