Change Website Meta Data

Issue-whenever I post a link from my website on linked in the image that appears as if the thumbnail is something other than my logo. I want the automatically created thumbnail to be an image of my logo. I've attached an example of what it looks like when I make a post. I want the image to be of my logo located in the top left corner of the [login to view URL] website. Proposed solution-I would like to change the meta-data on my website to control what appears as the thumbnail. Interesting points that might be pertinent- LinkedIn must've change something with their website because this wasn't always happening. In fact, the image that is populated on other sites like Facebook do not look like the images that show up on LinkedIn. Pertinent article-this article might be able to explain what I am trying to do more effectively. This link said it's possible but I don't know how to do it: [login to view URL] Lastly, I know that I can attach an image to each post in order to manipulate the image associated with the thumbnail. However, that is not an option for me because I posted these things automatically using a third-party application. Thus, I cannot manually insert an image to each post.