I've never known an animal sulk like the Dobie we lost about 12 yrs back, he'd come back from kennels, walk into the lounge, flop down in front of the patio doors with his feet on the frame and just stare down the garden for hours, we did notice as it was getting dark he would use the reflection in the window to see what we were doing. We could get his dinner and still be ignored, it was only when much later we opened the kitchen bin and started to (slowly) scrape his grub into it would he suddenly appear in the kitchen and start eating, after that he was our dog again.