They say that the sincerest form of flattery is imitation, and for Google, it may well be the case. Facebook has chosen to follow in Google's footsteps with how they display images uploaded to the world's most popular social network, as TechCrunch reports.
Photos are a big part of the overall usage of Facebook. Thousands of pictures are uploaded to the service daily, where they can be seen by an audience limited only to the number of users someone has in their friends list. Therefore it makes sense for the company to have a system for viewing these photos easily. It isn't hard to determine that, when a smaller service does something (arguably) better the bigger service will also need to do something similar as well.
This concept seems to have given Facebook inspiration for the direction of their new photo viewer. The current photo viewer forces a user to scroll down to see the comments. Google+ allows you to view the comments beside the image, which seems to suggest people are more likely to post a comment. The only problem with this so far is the design seems to allow ads to be displayed even more easily. According to TechCrunch, Facebook's design is not intended to make it easier for advertisers to get exposure, but when they appear like this, you're welcome to dispute the claim.
Impressions of the current photo viewer, known as the theater, were typically mixed upon the initial arrival of the system. Like all other features added to Facebook or changed, it was met with opposition by a vocal group while others tend to shrug it off and continue to use the service as normal. For anyone who has forgotten what the Google+ viewer looks like, see below for a clear parallel between the two:
Comparisons between the two can easily be drawn, and there have been a few claims of Metro styled buttons appearing in the photo viewer, though this may be a simultaneous test with the redesigned photo viewer or two different concepts that are being tested. As has been highlighted in the comments on the news article, as well as by PocketNow's Senior Editor Adam Lein, both photo viewers share more than a passing resemblance to Microsoft's Windows LIVE service, Skydrive. It would seem the current design used by both Facebook and Google+ is reflective of the Skydrive design.