Hello samanthaj9,
Let's see how we can help solve this.
If you haven't yet, try to close the Apple TV app on the iPad, then restart the iPad.
Learn how here:
- Close the Apple TV app: Close an app on your iPad
- Then restart it to test this out: Restart your iPad
After this, relaunch the Apple TV app and see if this issue continues to occur. These thumbnails should appear once you have established a network connection (through the Wi-Fi network). You'd need access to Wi-Fi and/or cellular (depending on the model) on the iPad to load the content within the Apple TV app.
In case this continues to happen, do you only notice this with a specific movie or show in the Apple TV app? As that may help us to change our advice moving forward.
Hoping to hear how it goes, take care.