The scene in which the girl writes a letter, puts it in the bottle and then throws it into the water, takes place simultaneously/ in parallel to the scene where the man gets in the boat, finds a gift and unwraps it.
These two aren’t logically connected, but they are brought togrther through a parallel perspective. They are two different scenes because it isn’t shown explicit link between the two.
The two scenes have elements in common. He is on a boat and she is in a port, so they are both in contact with water and are also alone.
So the environment is very similar.
The two scenes, although in parallel, seem to take place simultaneously: they are during the night

In addition the regist uses cold color in all scenes.
He is given a gift that is packed with a purple royal card, a symbol of elegance.
He unpacks the gift and he discovers that it is a book. She is rappresented while she take a bottle in her hands with a tablet inside, which she will eat it. She takes a sheet of paper and writes something on it. After putting the paper in the bottle, she throws it in the sea. We can say that the two scenes are connected by the fact that words are written in the book and meanwhile she writes a letter, so there are the words in common.
Both seem to have come up with memories that make them fell bad. These destroy them, bring much sadness to them.
Also the final scene unites them, because she throws the bottle with the letter into the sea and the gift card falls in the sea, too.