Google seems to be rolling out a new feature for the local knowledge panel named “inside this place.” Sergey Alakov posted on Twitter about it and it shows under the local Q&A box for some local businesses.
It shows inside photos of the business and then also lets searchers to add their own photos with a camera icon with a plus sign.
Here is a screen shot from Sergey:

This is not available for many locations but you can trigger it on a nice set of them.
Forum discussion at Twitter.