Please, update to our latest release if you haven't yet done so to gain access to more styling options. We are currently working on our Related Content feature in both the code and styling, presently experimenting with a double-line of recommendations as it has been requested by multiple publishers in our community since the release of version 7.
We haven't yet made a decision about this feature and are still tweaking the overall app styles, but we did recently release a new theme called vertical: as stated, the recommendation thumbnails are smaller and the title is beside the thumbnail rather than below. If you'd like to give this a test-run, you can modify your theme style from the 'Available Apps' screen through the 'Edit' buttons under 'Related Content'.
Because this app is currently under development as we further improve the feature, we will be making changes: changes in the options, styling, and in how it functions to bring your readers the best recommendations for your site.
The app placement options (Above Content & Below Content for your different templates) do not configure what content is shown, just where it is shown, but you can set an exclusion list under the General Website Settings panel to filter out specific pages from being recommended. This is a feature that was not available in our previous v6 release even though the same data was being processed. We hope this will help in tailoring Related Content for your site by allowing you control in hiding certain URLs from appearing.
And for recommendations where a thumbnail is not defined, you can easily set this up by way of the og:image Open Graph Meta Tag. If this problem is not affecting your entries (pages and posts) where the Shareaholic plugin is automatically defining this tag for you, there are several Open Graph plugins that can assist you in customizing this data for the other pages of your site, which will then be detected by the Related Content feature.
For those who prefer square thumbnails over the smaller graphic-window rectangular style, here's some custom CSS that you can include in your stylesheet (styles.css) to further customize the thumbnail appearance by showing a full square:
max-height: 175px !important;
Shareaholic version 7 offers many improvements and additional options over version 6 and boasts enhanced Related Content filtration. With each update we are rolling out even more improvements and have a ton planned as we continue to expand and refine the plugin.