Wrong Image or Title in Facebook or Google+ Share Window
Facebook and Google+ are getting the shared information from the header of your site in some tags that are called Open Graph tags. These tags hold information such as the image and title that the share window is using. If your tags are not displaying the correct information, then it is most likely your theme author that did something wrong in their code.
If your theme developer did not create the Open Graph tags directly in your theme, then you can add the tags by enabling them in the Basic Settings of Ultimate Social. You can also use a third party plugin such as Yoast SEO.
Facebook created an Open Graph Debugger which will tell you exactly what is wrong and whether your page has the tags or not. You can find the debugger here: https://developers.facebook.com/tools/debug/