The problem.
What happens when someone shares something, say a job description page, from your careers website on social media? The social network will add a sharing ‘card’ to your post with an image that represents the page, along with the page title and sometimes a short description taken from the page itself.
If you don’t specify an image for that social network to use (an “open graph image”) within the webpage, it’ll have a stab at creating its own… by picking a random image from the page. And, more often than not, the results aren’t pretty.
When it looks like this, would you click? We don’t think we’d be sold…