It shows how many british live abroad, where we all are, our ages etc. The main map has a button that changes the size of each country proportionally with how many of us have invaded. I think it's proportional as a percentage of the countries total population as the US barely changes while France bloats up (although still nothing compared to Spain, which is going to burst and spray cheap sangria everywhere).
There's about 200,000 of us in France, mostly working age (not like the Eastbourne of Europe, otherwise known as Spain). Coming the other direction there's only 100,000 french in Britain, so it looks like we're winning!