My boy JC (actually he's my daughter's cat, but stays with me most of the time) loves to purr. We tell him he's the Purr Master, with the MasterPurrBox. With him, it seems to indicate that he's very happy with life in general. Almost any situation will elicit purring, whether he's relaxing & just giving me those loving eyes, or watching birds through the window, or playing etc. Your Lil Rascal is adorable; from those bright intelligent eyes & alert expression, I'd say he's purring cuz he has Joie d'vivre!