Hello RSG,
Thanks for the screenshot.
This is a Chrome OS exclusive feature called Emoji Picker. It was introduced in Chrome OS v92. In the recent Chrome OS v117, Google added GIF support in the emoji picker. As this is an integrated part of the Chrome OS, Safe Doc has no capability to block them.
Go to Google Admin Console > Devices > Chrome > Settings > User & browser settings > User experience > GIF Support in Emoji Picker, and select the policy to Do not allow GIFs to be selected in the Emoji picker.
I hope it helps.
Cheers,
-Jason