I remember how Yandex was making a toast out of Google image search (market share wise) by providing said button. I think that the whole inclusion of the button

I remember how Yandex was making a toast out of Google image search (market share wise) by providing said button. I think that the whole inclusion of the button by Google was motivated by this competition and Russian market was the first to get it. Guess what, I think yandex.com still has it too.