Feeds that include images, videos, and gifs in tweets are available with the “Pro” version of the plugin only. Here is a list of possible reasons media are not displaying:
1) You have the “free” version installed and activated.
Navigate to your “Plugins” page and see which version of the plugin is activated. The “free” version is titled “Custom Twitter Feeds” while the “Pro” version is titled “Custom Twitter Feeds Pro”.
2) Media are excluded on the Settings page, “Customize” tab.
Under the Show/Hide section, make sure that the box next to “Media (images, videos, gifs)” is checked.
3) An add-on or extension in your web browser is blocking the images
You may have an add-on or extension you have installed in your web browser (often Firefox) that is blocking the photos being loaded from Facebook. Try checking to see whether you have any add-ons or extensions installed in your browser and, if so, try disabling them to see whether that solves the problem.
Another possible reason for images not being displayed is if you’re browsing using Firefox’s “Private Browsing” mode and have “Tracking Protection” enabled in the settings. You would need to disable this as it blocks some Facebook images.