Sometimes you aren't really looking to see anything, you're just letting your eyes get distracted so your brain can do its thing. But where your gaze lands can have a surprising amount of influence over your thoughts. This is one of the reasons we seek out beautiful places to live, stunning art to decorate with, and pleasing colors to fill our world. Looking at drab concrete and plain walls all day leaves you with drab, plain thoughts. Seeing the same sight every day leads to thinking the same thoughts every day. Gardens that change with the seasons, sculptures that shift in the shade of the day, paintings that play with the temperature of the lighting as the sunlight gives way to human light, and skylines with clouds that float and glow and churn, these are the dynamic aesthetic systems that renew our idle minds.
See this fractal animated here.