This picture is from a magazine scan, which is why it's kind of blurry. The Winx girls seem to be casting a spell (notice that their hands are glowing and they have some kind of ripple [Portal?] below their feet).
They're wearing the same dresses they were wearing in the poster. But once again, there's no Roxy. Since there are no images of Roxy, can we pretty much say that she won't be in the second movie? Let's not draw any conclusions right now...we might be in for a surprise ;)