favicon in Yandex and Google services

I'm already half a year interested in the question: cann’t google really draw icons for its services? Or they think it doesn't matter.
Here is what I mean:

I will explain.
The first group of icons are Yandex services that I often use. I think it makes no sense to paint where what.
But the second group - Google services. Um ... who is who? In principle, I am used to the fact that the second one is gmail.com

I appeal to people who develop various web-services: do not be lazy to formalize your work, perhaps this will make life easier for someone.

ps do not hit hard, the first post.