I would like to suggest adding website favorite icon in tabs tray

That's really too much in my opinion. Why do I need a favicon when there is already a website thumbnail? In your example screenshot it's in no case useful.
@cadeyrn Sometimes you can't identify what the website from it's thumbnail and if you open a lot of tabs the favorite icon will make it easy to identify it
This sounds really useful to me, especially when trying to identify one site with many tabs open.
The only possible issue I see is performance-related: Drawing a large amount of favicons at the same time could be CPU-intensive.
@cadeyrn Sometimes you can't identify what the website from it's thumbnail and if you open a lot of tabs the favorite icon will make it easy to identify it
The URL of the resource is shown for this reason.
I can see a favicon can help. Maybe as an option to only show favicon instead of page screenshot?