Revealing: When Annette Bening climbs out of the bathtub, you can see that she is naked underneath her bathing gown. When she gets back into the bathtub, you can see that she is wearing black underwear beneath her gown.

Revealing: When Annette Benning reads the letter in the bathtub and shows it to Colin Firth, before the ink begins to run, you can see that it is just squiggles on the paper, not words.