There isn't too much to show here because, obviously, I don't want to display Philippe's address. I think it isn't evident from the picture, but it took a lot of time to draw and paint the letters using watercolours...
And about the stamps, they belong to the philatelic series
12 Months, 12 Stamps, 12 Provinces. Correos issues stamps dedicated to every province (there are 48 in Spain, plus 2 autonomous cities). During the month of the issue, that stamp is used as the only type of postage for all post-office shipments sent from of the featured province.
The design of every stamp is based on the old license plates once used for vehicles in Spain. Inside the letters, you can see typical things of every region, like flora, fauna, food, inventions, architecture...
And I can help but tell you about a funny story.
On the stamp dedicated to the province of León, you are supposed to see the cathedral of the capital of the province:
León. But,
during the official presentation of the stamp, a women from the audience said that she didn't recognise the cathedral depicted, but certainly it wasn't the cathedral of León.
After a short discussion, they discovered that it was the cathedral of the capital of a different province:
Burgos. The stamp was already being used. So, they decided to issue
a new stamp, with the
right cathedral.