When sharing a link a with BP Activity Plus, it should pull the meta description for the displayed snippet before it pulls from the body content.
I only thought of this the other day when I was sharing a link to a blog post and the first paragraph was displayed. It was well written, but the character count that Activity Plus pulls actually made it look bad. I took a look at the source code and saw that the meta description for that post was clear, concise and well-written...and much shorter. It was a good summary about the blog post.
Good SEO practices encourages folks to use software to provide good meta descriptions for their websites. Activity plus should take advantage of the effort folks put into it by first pulling the meta description for the snippet, then, if one isn't present using the body content for the snippet.
I think this will make for better and more useful link sharing.