How to load website from macOS as if using iOS for this particular website in safari? I tried to watch live stream from cbsnews, however installation flash is required. I don't want to install flash, so I set Develop -> User Agent -> Safari iOS 10 as usual try to deceive the website that I'm using iPhone. However it didn't work. How does it recognize the device I'm using?

Is there any way to watch this live stream without using flash?
I assume you have Google Chrome installed? Open the link in Google Chrome and click "enable flash." A "pop up blocked" message will appear at the right of the search box. Click on it and enable the website to use Shockwave Flash.

You do not need to have installed Adobe Flash using the Adobe Flash installer on your Mac for this to work.