https://www.youtube.com/watch?v=CyUGFI79KzM#t=2419

I had a casting recently and I must improve my walk and overall presence. I'm very shy in person as you can see and most agents view it as... Well... You'll see. ;-;
@38:55

I feel most of the "shyness" comes from the your shoulders being a bit hunched. Pulling them back and protruding the chest a bit will add authority to the walk. Perhaps the chin up a bit, but I don't know what or who you were looking at. My big thing is that I feel your step sometimes doesn't lead. When you place your leading foot in front it doesn't always land in a uniform place, so it makes the overall walk look a little chaotic.

Overall you did a great job though. Seriously. You should be proud!