Vide grenier - literally 'empty the attic.' Perhaps we'd call it a bric-a-brac sale or a garage sale.
You might recognise this square - the church is to the left and recently I posted a photograph of a brass hand (door knob) and the next day the door and facade. It's the same door you see on the left. Click on the link to see how different it looks without the children's clothes and toys.