Google is now allowing developers to embed Photo Sphere in addition to Street View images in Google Maps on their own websites. The capabilities are now part of the Google Maps Embed API. Previously, web developers were able to embed a Photo Sphere that they had captured, but not public ones. The latest change allows you to embed a public Photo Sphere from Google Maps into your own website.
The embed would show up as it is shown below:
Today, we added the ability to easily embed the Street View and Photo Sphere images you find in Google Maps and we're also enabling the same capabilities programmatically in the Google Maps Embed API. These embeds use the new imagery viewer technology that powers Street View in the new Google Maps.
To embed a Photo Sphere from Google Maps, you'll have to hit the settings cog at the bottom in the Google Maps view, and Google will present you with a URL or embed code for use in your own website.