Fair point. My browser (FF) supports 'search in tabs' as well and suggest it over a new search engine result when typed in the address bar.
I don't know what about the style makes me think this, but it looks like FF on Windows in the Screenshot.
Love seeing a GNOME rice, I tried some GNOME ricing on a Fedora myself, however I was unable to get any further than installing Extensions 'Just Perfection' to hide some elements or using 'Burn my Windows', which I loved.
What did you use to style your GNOME-Shell Components?