I spoke with the BoldGrid team directly and they said that this information is being pulled from the gallery that is rendered in shortcode at the start of your page. He said that you can use the BoldGrid SEO plugin to add a custom description that will take the place of the other one. You would need to request a recrawl of your site by search engines in order for the change to appear quicker. Otherwise, you would have to wait for the search engines to crawl your site before you would see the changes appear in the search engine results.
I would also advise that you make sure that your plugins are updated. All of the versions you listed are old except for the theme, gallery, and the staging plugin. Make sure that you backup EVERYTHING before you make any updates or changes. That way you can recover in the event that something unexpected happens.