When you visualize stuff you want, you keep a look out for that same stuff. You attract what you visualize because you keep looking for ways to get to them in your environment.
For example, if your mind is constantly dominated by images of red cars, you will automatically start searching for red cars on the street or noticing them more than usual. Or, if you’re dominantly thinking about happiness, you will find ways to be happy in your environment. Thinking more about wanting/having success rather than not wanting and avoiding failure would perhaps work in the same way.
So I don’t buy the whole “the universe realigns itself for you” theory in the same way its talked about in the book. However, I think that that does happen metaphorically because when your mind is dominated by images of things and situations you want rather than the ones you don’t want, the way you perceive the world also changes. You start searching and seeking ways and opportunities to manifest your desires more, and you may even enhance your drive to take action to achieve those things, hence getting into the mode of inspired action. Instead of becoming dull, you in fact become more motivated to go out there and exploit all the opportunities around you.