The UI/UX on this product is not that great. Google is offering a similar solution as Kayak. But I'm not sure why they just didn't fully copy Kayak. It feels to me, 1 - google thinks they are smarter than Kayak, 2 - they didn't want to show they are copying Kayak.
For example, kayak does a great job of displaying all the options on the left column. Google is hiding everything in drop downs. So then they need to have a blog post to explain how their UI works where kayaks is just intuitive.
The same with bar chart pricing (which I like) why hide it behind a silly icon like that. Now they have to educate their users what that icon means. Call it "best days to fly" or even better show that at the bottom of the page.