The trailer is pretty straight-forward as trailers go, with a succession of short moments from the new series and a narration by the Doctor over the top. There’s less to unpack from this than there was in the teaser from a few days ago, but what this trailer definitely has in spades is a sense of wonder and excitement. The shots and scenery viewed are simply gorgeous. Intriguingly, there isn’t a single look at any monsters or aliens. It focuses on the Doctor and her three new friends, without even a single other character appearing. But that’s okay, as far as I’m concerned. I like the greater secrecy being kept over this series than in previous years. It helps increase the excitement factor. I, for one, can’t wait till it starts!
(Edit: A few other characters do appear in the trailer beyond just the Doctor and her companions. They appear during blink-and-you'll-miss-them moments, but they're there.)