Il ne faut pas mélanger torchons et serviettes. Originally, this proverb has a strong social connotation: tea towels are for the poor and the servants, napkins for the bourgeois and the aristocrats. And one should never mix the two, socially, or otherwise.
Carré d'agneau is a side of lamb chops. A carré is also 'argot' for a square-cut, bob hairstyle. This square-cut sheep is in its element on the mountain slopes.
We all know ‘The Laughing cow’ cheese. It’s literally translated from the French brand ‘La vache qui rit’. This cow prefers playing the game of quille, a type of skittles played in SW France.