If Facebook doesn't seem to be posting the most recent text and image you added to the Social Media section, you likely need to run a Facebook refresh.
First, make sure your Social Media settings are what you'd like to share to Facebook.
Save and publish your changes if needed. Then copy your page's live URL.
Copy the URL into the Facebook debugger below.
Click 'Fetch new scrape information' then click 'Show existing scrape information'.
Now when you share to Facebook, your updated details will post.
Note: If the image isn't showing up at all, check to see if the file name has any spaces in it. That can sometimes result in a blank image. To remedy that, you can rename the file with no spaces - re-upload the image - and publish on the RedPodium side. Then return to the Facebook debugger again.