Okay, so this is likely obvious information, but I decided to look around at the office buildings that Nintendo owns on Google maps and other misc photos from these two images. The most obvious sign for the buildings in the tweet were the darker tiling beneath and across the top of the building.
Looking at Google Maps and pictures of the office buildings in Kyoto. Nintendo Central Office and Nintendo Kyoto Research Institute do not line up with the image. That said, Nintendo Kyoto Development Complex does fit the bill. Looking at Maps, there are a bunch of leaf-less trees from February 2022 next to the building that cannot be seen at that low of an angle outside of the office. "Bingpot" one might say.
So what does Nintendo Kyoto Development Complex do? Well they house the Entertainment Planning & Development (EPD), Platform Technology Department (PTD) and other Business Development divisions.
The problem is that, with both of those divisions being in the same building, it's hard to say with any certainty that it's a hardware-related thing or a software-related thing. However, the reporter in the image is from Bloomberg, with Mochizuki mainly focusing on hardware. It's mainly hardware like the PSVR2, Japan's hardware chips and of course the Switch 2. He also discussed Palworld and a relation with XGP a lot in recent times, but that was a big hit so fair enough.
So pretty much, I have little reason to not suspect that some chicanery is afoot. There's no reason for Mochizuki to be invited to the Nintendo Development Complex for a demo of software. It's most likely a hardware demonstration or a formal meeting about something related to Switch 2. No idea what, but I am a lot more interested in this story with this context in mind.