First of all, Mocchi was/is at the Olympics:

Anybody know if she's there for work or is she on holiday? Is that even possible

Secondly, Mocchi is one of the members with the most trips abroad. Especially when it comes to Europe and the USA. She was at both European shows: Japan Expo 2009 in Paris and at Mipcom 2009, Cannes. IIRC she was at all the shows in the USA as well, or at least two of them. She was the special guest in the foreigners AKB48 quiz show and now she's in England!
Long story short, does Mocchi have something which makes her likable to westerners? She doesn't speak English, she's pretty but so are hundreds of others girls in the group, she's not a halfy... Why her?
If we look at other girls who've been abroad a lot, we end up at girls like Akicha, Sasshi and Rie, who were like low senbatsu/high undergirls at the time. Would the explanation simply be that it fits their schedule and have enough appeal without being the top girls, or is there something else to them? Mocchi especially?