Tristan was disgrumpled because Guinevere had a Targeted Go Find with an *entirely new* target and Tristan DIDN'T. Tristan couldn't even HELP. And Gwyn was soooooo bad at it (she takes longer than he does), very frustrating for a very competent, very earnest Young Man to have to witness.
Tristan later had his own Named Toy Selection training session and was content. He just had to fully express his opinions about the situation.
[Video Description: Tristan, a black and white cocker spaniel in a crate, picks up and drops a plastic pill bottle while making complaining noises. He looks to one side and makes a few more Sad Tristan Noises. Guinevere, a red cocker spaniel, trots up to the crate and sits, trying to offer encouragement, but Tristan cannot be soothed. Guinevere trots toward the camera, as Tristan picks up his bottle again, drops it, and complains some more.]