Now that I've finished it, I can say this had a great reveal! It recontextualizes the whole game and even the title screen. It's a well-conveyed, lovely story too. I really like the new addition you've made too - where while Scarlett's chasing the dog the music gets quieter and the city noises get louder. I'm pretty sure it's new, anyway.
There are still a few bugs. I can still make Scarlett walk under the tall plant I mentioned before. And you might want to check the lampposts/objects outside, I could walk under several. Also Scarlett briefly disappears the last time you interact with the dog before her sensory overload. I think that happened the first time too, but I forgot about it. But those are smaller bugs that you'll probably work on later.
Nice work!