It was driving me nuts- I wanted to show all my followers a really cool photo I saw in someones galleries on google plus and there was no SHARE option. Well, I figured out a little secret on how to do it; it’s actually quite simple.
Go to the photo that you want to share, and leave a comment on it. It will end up in your stream with the option to share or comment. Voila!! Click SHARE and you’re good to go! Simple easy workaround for something that should be common, right??