Paréidolie : n.f. Sort of illusion based on the tendencyto interpret a vague stimulus as something known (shapes in clouds, constellations...).
French grid : "Trésor de la langue (12) : paréidolie"
Difficulty : ****
Tested, logical.
Not require any specific method, only single-line logic.
Good "blackenage".
Thank you for the puzzle!
Que voilà une nature morte pleine de vie !