Well, for example, I've noticed that ballet dancers (that have no ballroom experience) have a tendency to walk a bit duck-footed, but in a very particular way. Instead of most people that walk duck-footed (which is natural), it appears that their foot falls in a specific way... I have no experience with ballet personally, other than having some friends growing up that did ballet, so it's a bit hard for me to explain. Maybe something to do with the sequence of how they land their heels/balls of their feet? Also, I've noticed that quite a few ballet dancers, as soon as they stop walking, tend to end up in one of the ballet foot positions (I believe it was called 4th position or something?).
Some walk on their toes or at least with a toe lead, and yes, in a very specific way.