The original image comes from at least 2 years ago (2011) so no surprise why they aren't included. I'm pretty sure someone at Yahoo just saw this when it was reblogged on tumblr a few days ago.
RE: a potential sequel, its a risky business as you've created expectations for it that an original IP isn't burdened with. And I don't mean expectations of equal or greater quality, I mean what people expect to see based on their own interpretations. Just look at Elsa; no romantic interest in this movie so now everyone has their own expectations for what should happen in a sequel. Some people think it unfair that she didn't have a romance and want it fixed, others think it was one of the strengths of the film that she didn't and still thrived in the end. Some people imagine her as being normal heterosexual, others see homosexual subtext in her story, but because there's no firm indicator either way, both are equally valid as each other until the sequel comes along.
Then of course some people wanting an explanation of her powers, or to meet other people with abilities, like the oft mentioned fire powers. I personally am happy not knowing why Elsa can create Ice and Snow. To me, it seems more personal to her character that she was simply born with these gifts, and that they're just a part of her, than if they were the result of a plot point. And I seriously hope they can think of something a little more original than fire as a power if they go down that route.
As for my expectations, since reading up on The Snow Queen, I've imagined a sequel that includes more elements from the original fairytale, like the evil mirror or the robber girl. But considering a large part of the success of this movie is due to it being it's own story, would that kind of thinking just hinder it?