It's already there, but there are only a few websites supported: https://github.com/signalapp/Signal-Android/blob/0ef01cc620cc907da6078c93cc97d31e6612b3f3/app/

It's already there, but there are only a few websites supported: https://github.com/signalapp/Signal-Android/blob/0ef01cc620cc907da6078c93cc97d31e6612b3f3/app/src/main/java/org/thoughtcrime/securesms/linkpreview/LinkPreviewDomains.java https://github.com/signalapp/Signal-Android/blob/0ef01cc620c... If you opened a PR with the websites you're missing, I'm sure they'd be open to it. I see sibling comments mentioning that they wouldn't want this feature (which is already there) because of its privacy implications, but I think that it basically works like gifs, with a proxy controlled by Signal.