Similar to a bruh moment, it's when you do something so idiotic that you look at the camera in a similar fashion to old cartoons, and your physical appearance is similar to Walter the Dog from the Walter memes.
Zach had a walter moment when he missed a note on funny family-friendly rhythm game known as osu!
If you‘re getting sick of someone who doesn’t care about rules. Or someone is trying to cheating you.
Someone is blathering about a subsequent event in a project meeting and try to convince the audience to follow his approach. Joe in the audience just asked Ed if he gets tired because his eyes are closed from time to time. He replies: “No, no... I am just having a Walter moment!”