As long as the folks who came to the EU one didn't follow the pictures and stuff being posted too closely hehe - I doubt they would, as they are not as rabid as us on the forums. Be like getting Disneyland Paris compared to the one in Orlando! I kid, I kid - don't hurt me!
I think it was their own offices in London eh, so I guess that it normally would be a pure work environment - rather than, as you say, a venue rented out for the specific purpose - we spruce our office up from time to time for visitors, but you can still tell it is a work space in day to day life. Still, they put the effort in, and the main thing is that Yoshi-P was there (and the software). Such a shame that it was temporary though, must have been a nice environment to game in, however briefly.
Funnily enough, he mentioned the sun eh? Well, I live in Scotland, and the past two days have been the only ones in absolute months that haven't been rain, snow, or a mixture of the two - that or gale force winds. Please Yoshi-P, don't leave the UK, we need you! Either that or all the interesting news has pulled me from under the dark clouds of depression, but I think it honestly has been miserable weather :3