Rather looking into the whole internet stuff, user after typing the search query can simply go to the personal tab to look for the results which are only meant for the user.

Also, to look into the things you have in your Gmail e.g. lists, documents, pictures etc. this tab helps in searching easily. The new feature isn’t something out of the ordinary because the technology was there as user could always search through private Google Photos and the Gmail accounts from Google search as far as the user is login.

However, new tab just make it clear or to say it loud visibility factor increased in that case. Example, if you type Oman in the search, you would get mixed results like images, wiki links and so on but in personal tab you’ll get the stuff only related to you either placed in Google Photos or Gmail.

Official announcement from Google isn’t made public yet.