Each of those is not a picture, but a clip from the video which is shown on the actual article page. I'm guessing that this is a problem with your browser, or a setting in your browser.
Works fine in Chrome, and Firefox for me.
If that doesn't work, reset Firefox as follows:
Click the 'hamburger'. (Three lines, top right).
Click 'Add-ons'
Click 'Extensions'
Note down the names of any extensions you're using and wish to retain ('cos you're about to remove them!)
Click the hamburger again
Click the question mark (bottom line)
Click 'Troubleshooting information'
Click 'Refresh Firefox'
Return to 'Extensions', search for and install the extensions you want.