On my last trip to Panama I noticed my photos spheres were showing along with the photos automatically uploaded from my phone through the Google Photos app. However, when you're looking at the sphere's in an album view, they show up warped and weird (i.e. flattened). Then I discovered the trick - click on the image. Photos appear in a large format and *photo spheres load up*! Now I can see the 360 effect from within my photo album.
Here's an album that contains some photos as well as spheres. Remember, click on the spheres to get the full effect!