OK. Let's have a closer look:
First shot - and we're in the Swiss Alps! Slightly worried about the obvious CGI work here (understandable as it is, given the budget). The location is taken from 'The Erymanthian Boar', which is the central story of the adaptation (judging by this trailer and the press releases so far).
This is a new character, not present in any of the short stories: Francesco, the owner of the hotel. Fake snow! Hooray.
...aaand more fake snow! The location used is Halton House, Aylesbury.
Here's our leading man. In what looks like Murder on the Orient Express mode? (He's wearing the same coat, scarf and hat)
Now, this is where they lost me. What's going on with the sunglasses? This is in front of the mountain lift they use to get to the hotel (actually built on location next to Halton House, and covered in - you guessed it - more fake snow).
Poirot in an apparently empty reception. This has a sort of At Bertram's Hotel-feel to it, don't you think (not entirely sure if that's a good thing).
So... what's going on here, then? The girl with the necklace is Lucinda LeMesurier (a reference to 'The LeMesurier Inheritance'), according to the press pack.
A painting is missing! 'Hercules Vanquishing the Hydra', according to the press pack.
Something sinister is going on. Very James Bond-ish.
More fake snow and CGI! (But those mountains look quite impressive, actually).
Here's a waiter who doesn't know what he's doing...
Poirot seems to have figured it all out (or has he?). It's his signature 'ah!' move.
Someone is having a bad day... And more James Bond effects!
What does everyone think? Judging by the press pack interview with director Andrew Wilson, we're in for a very dark episode exploring Poirot's journey of redemption and retirement.