Adding a Featured Image for an Article
To select a featured image, choose set featured image on the right, upper part of the posting page. Make sure you have the proper naming convention.
After selecting set featured image, you will see this page.
You may select a file from the images you have already inserted into your post by clicking the Gallery tab, or select a new file to upload by clicking Select Files. After uploading your material, you should come to this page.
Make sure that the Thumbnail 150X150 pixels setting is selected, and click Use as featured image. Close this by clicking the X in the upper, right-hand corner.
You should see your featured image (thumbnail) upon returning to your Web post. If not, you need to redo the process.