Gargoyles are the symbol of Notre-Dame de Paris.
They are the guardians of stone, immobile and eternal, who observe in silence, day and night, Their Lady to protect her from external threats.
We can be like gargoyles: we can protect and preserve artistic heritage, the containers of our soul and our history. We can be The Guardians of Art.

The postcards are a tribute to Notre-Dame de Paris following the fire of April 15, 2019. On the back there is a phrase taken from the work The Hunchback of Notre-Dame by Victor Hugo:

The saints were his friends, and blessed him.
The monsters were his friends, and guarded him.