I couldn't sleep until I found the cursed use-case these serve.
I think I found it...
Apparently some ebike chargers output DC on a C13 connector:
bkhome.org/news/202411/...
So I'm guessing the adaptors are to allow those chargers to attach to different ebikes.
I need to have a lie down

Pretty fancy!

> Anzac Station’s distinctive timber canopy is 85m long and 23m wide. It’s designed as a pavilion in the park that blends into its leafy surrounds. The canopy sits on massive steel columns up to 17m above the station concourse with skylights that draw in natural light.

It's Anzac Station, which is part of the new Melbourne Metro Tunnel project.
openhousemelbourne.org/event/metro-...