Google Photos looks as though it is being readied to take better advantage of the already-available object and person detection that it offers. In particular, it seems as though Google is going to push face recognition as a much more prominent and usable feature in the future. The details on this are still a little sketchy, and are based off a teardown of the latest version of the Google Photos app by Android Police.
The sum of the information is that Google is going to place a much stronger emphasis on Google Photos' use of face recognition. This is for you (the Google Photos account holder) and people you know. The latter is of particular relevance as the information seems to suggest there will be an ability to share images (presumably) with people who have been detected in those images. Which brings us to the 'you' part. According to the details, Google Photos will first start to ask users to select an image which identifies them as them. Once selected, it appears Google will also ask users if they want to make that face publicly available. And this is presumably where the share feature will kick in. As not only will the feature effectively allow other people to identify you in images that they have taken, but it will also be the backbone of the share function. If you select to share an image with those in the image, then providing they have also given permission to be identified, Google Photos will know who to share the image(s) with. Which is different to how Google Photos currently identifies people in images, locally.
Of course, not everyone will want to be identified and not everyone will want to share images they have with other people of themselves, or even of, those other people. So it also does seem clear that Google will be making all of the mentioned features optional. If you do not want to use them (or some of them), then you will be able to opt in or out depending on your level of comfort. As always though, there are no details on when the feature which actually go live, as at the moment, it is just the behind the scenes aspects that have been spotted. Not the actual features. Which does also lend to the notion that they are subject to change before being made available, as well as the reality that they might not become available at all. For reference, this is the currently available version (updated yesterday) of Google Photos.