I've been meaning to add sixel support since forever, but I like my way of doing it so much more because it supports the file formats people use, which are generally a much better encoding than sixel. That being said, this is nicer than iTerm2's equivalent (called imgls) because it re-encodes the image to make it smaller over the wire. That being said, I'd rather use a lot of bandwidth than have to install imagemagick everywhere. That's probably just my bias against dependencies showing :)