I'm a drama teacher, so forgive me my slight detour - but the photograph at the top is exactly the right way to interpret most American plays. They're often about a family unit who spend 3/4 of the play smiling at each other - and to us British readers, not much seems to be happening - the play doesn't go anywhere, then in the final quarter there's a brutal murder or someone digs up a child or someone gets brutalised because the first 3/4 is almost always coded dog whistles. This photograph shows that play exactly. Smiles, Christmas, chirpy people - but I bet two of them are secretly fucking and the final twist will be the kid on the right going on a rampage. That's how I'd write this play at least :o)