To you or me, it might not look like an ideal theme for profound cogitations. But, for Sophia and Fitzroy, this small unidentified turd on the macadam (in front of Fitzroy's snout) needed some explaining.
I don't know what conclusions they reached. If the dogs had asked for my opinion, I would have said that it had been dropped during the night by a fox. But I don't have anything like the amazing olfactive apparatus of a dog. So, my opinion doesn't really count. Sophia's expression suggests that she has made her mind up concerning the nature of the turd, and is now wondering where the animal in question might have come from. Fitzroy's position, on the other hand, suggests that the little dog thinks the turd-dropper might still be hanging around in the vicinity. Ready to attack, Fitzroy seems to be wondering how he'll recognize the intruder.