The woman is snarly and her dog has picked up on the vibe. She is small and uses the dog for (perceived) protection.
Next time you see her tell her to get a dog trainer as dogs in built up areas will inevitably see lots of others out walking with their owners and the onus is on her to ensure that her dog doesn't attack other people's dogs if she doesn't want to have to face legal bills should there be an unpleasant outcome from her dogs behaviour.
Funny how owners often seem to look like their animals. That sure is one ugly looking dog.
