Everybody has their personal opinion...everyone knows mine and I PERSONALLY think both girls looked great but Adriana is more beautiful IMO, but Doutzen looked stunning at this event as well, it's a matter of personal taste. The two represent totally opposite ends of the modeling spectrum Adriana the gorgeous Latin Beauty and Doutzen is the classic beauty, doesn't make either less appealing just makes them appeal to different people.
I think Doutzen was a little stiff at this launch, and a bit nervous but they couldn't have paired her with anyone better than Adriana, other than the lead angel and baby angel thing (I don't count Heidi ugh) Adriana use to be very very shy and very reserved because she really was new to the whole launch thing, and now she's a pro, now Doutzen was a bit nervous, and stiff and maybe after working a little and being with someone who had been in her shoes will help her.
I think she'll do great and be a great addition to the squad.
And as for their choice of clothing, it was picked out by the people at VS. The stylists pick out the outfits the girls will where for every event, the only events they don't have to pick out is any "After party" event, then it's all up to the girls.