Assuming instead you want a preview image of a web site to be displayed by default without user having to hover over a link, you can do that with the ShrinkTheWeb (STW) Website Previews Plugin.
Step 1 – Register for a ShrinkTheWeb account:
1. Register at https://www.shrinktheweb.com/user/register
Step 2 – Install the WordPress plugin:
1. Go to your WordPress admin site
2. Navigate to Plugins > Add New
3. Search for ShrinkTheWeb
4. Click Install Now button
5. Click OK to install
6. Click Activate Plugin to activate
Step 3 – Configure the WordPress plugin:
1. Click Shrink The Web bottom of WordPress admin menu on left hand side
2. Copy Access Key from your ShrinkTheWeb Lobby page into Access Key Id field
3. Copy Secret Key from your ShrinkTheWeb Lobby page into Secret Key Id field
4. Click Save ALL Settings button
Step 4 – Add web site preview to WordPress page
Non-hyperlinked preview of a web site
Include this in your page, replace the URL with the one you want the preview of:
[thumb]https://startingwp.com[/thumb]
Hyperlinked preview of a web site
Include this in your page, replacing both URLs with the one you want the preview of:
<a href="https://startingwp.com">[thumb]https://startingwp.com[/thumb]</a>