YouTube Music app users on iPhones and iPads will see music video previews in the player view. The preview will only play for a few seconds and without any audio.
If you want to continue viewing the video after the preview, you can tap to play it. To turn off the preview mode, or to only play previews while on Wi-Fi, read below.
Note: Music video previews only play on iPhones and iPads. Currently, you cannot turn this feature on or off on any other device.
Only play music video previews on Wi-Fi
To play music video previews only while using YouTube Music on Wi-Fi:
-
Tap on your profile picture 
in the YouTube Music app 
.
-
Tap Settings 
.
-
Tap Playback & restrictions.
-
Select Show animated thumbnails.
-
From the section that opens, tap Wi-Fi only.
Turn off music video previews
To turn off previews of music videos while using the YouTube Music app:
-
Tap on your profile picture in the YouTube Music app .
-
Tap Settings .
-
Tap Playback & restrictions.
-
Select Show animated thumbnails.
-
From the menu that opens, tap Never.
in the YouTube Music app 
.
.