Stop google+ using peoples avatars for sharing posts

[boro_boy]

When I go to share a post on google+ it brings up the image of one of my members avatar, how can I stop including member avatars as the main image when i'm sharing posts?

I have the correct meta tags for google which uses og:image

My og:image is 

But this never comes up, its always the Manchester United image??

 

Thanks in advance. 

 

 

[opentype]

The og:image might be too small. Just a guess. 

[boro_boy]

Thanks for your reply, i've re-made the logo to be 500x500px the previous one was 200x200px which was the minimum. Below are the images I can choose from when sharing my sites main forum index page.

 

[opentype]

Yeah, looks correct now. That’s the result you get with stock IPS functionality and a suitable sharer image. 

Here are some more tips from Google: https://developers.google.com/+/web/snippet/article-rendering

[boro_boy]

I would only like to use the sharer image and not other peoples avatar / profile image. I take it thats not possible.