I have found this article from a web site. it talks about the meaning of the picture, The love letter.
Pulling a curtain to one side, a scene of domestic intimacy is revealed. A well-to-do woman, clothed in yellow, is being handed a letter. She glances up questioningly at her maid and pauses in her lute playing. The room with the two women is brilliantly lit; the space in front of it is darker. Sheet music can be seen on a chair. Perhaps the lady is waiting for a person with whom to play music. On the dark wall at the left of the door opening is a map. Vermeer signed the painting with his characteristic signature, compressed on the left, next to the maid, is the name ‘JVMeer’.
Although the lady has not yet opened the letter it is apparent from the picture that it is from a lover. The two pictures in the background indicate this. A painting within a painting often indicates the artist’s intention in the picture. Here the lower painting is a seascape. In the seventeenth-century language of imagery the sea stood for love, and a ship for a lover. The emblem written by Jan Krul ‘Far from home, never far from my heart’ expresses this well. The upper picture shows a man walking along a sandy path: as in the painting of the ship, there is the suggestion of a person on a journey.