This is my take:
They were lovers for a few years, breaking up 15 years ago. They had hoped for a life together, but he was going nowhere, treading water, getting deeper and deeper into alcoholism. She left him.
Now, happily married, living in Paris, a couple of children, she gets a call from him to have lunch when she comes to London. She accepts. Her deep hope is to find her old love improved, getting on with his life, and happy.
She hopes for too much. He is still in love with her, but in a dreamy, alcoholic sort of way. His Great Love is alcohol. He has gone nowhere and done nothing. She is so disappointed.
So is he, but he drinks that, and all emotions, away ____ away.
I feel pretty sure makeup had worked to make him look dissolute. And yes, Emma looked GREAT! I loved her hairdo, but even more, I loved that dress. I kept staring at the marvelous way that neckline was created and imagining all sorts of frocks and tops made in that fashion. Very feminine and flattering.
I found it extremely touching when the moment came that she was feeling so sad about finding him unchanged and stuck in time and still addicted and she reached out and touched his hand. She HAD been so very fond of him once, and the sadness of the death of those feelings and sorrow for him just overcame her. WELL acted!
I have seen sooo much of this in real life. I found it exquisitely acted and very short. Beautiful. Beautifully done. Both actors beyond superb.