Looks like the Vivaldi community forum isn't fully new.
There's some things which doesn't show in the new style of Vivaldi community forum, but in old style.
This link is copied from Chrome Web Store page of “Image Autosizer” extension for Chrome
@Piter432 The update of the blog part was delayed because of some problems with a upgrade to another blog software.
Please stay tuned.
@Gwen-Dragon: Okay, I didn't follow the updates of Vivaldi community sites, so I didn't know
Thank you for info!