yeah i shouldve gone into more detail. my idea of pomposity is more aristocratic and aloof, rather than extrovert cocky swagger. but its semantics, pomposity can apply to both.
im not an animation expert but the way i see that stance i mentioned translating into a walk: a quite static upper body, arms held rigid, chest puffed out, long confident strides. could go different ways with the legs really, could glide gracefully with very little vertical movement, could almost march, stiff-legged, with some pronounced vertical movement or like a military parade, not much. you could definitely add your own ideas there based on the imagined eccentricities of the character
might not apply to your dude (he might not be posh, or a British WW1-era Colonel), but thats just where the word pompous takes me personally.
edit: i think as well the walk im thinking of would look much more pompous in profile