Because it only works via the Mlmym frontend, supposedly. Give it a go: https://o.opnxng.com/lemmy.nicknakin.com/

I haven’t tested it myself. I hate scripts with dodgy website checks. The author should have hardcoded the known Mlmym instances instead. (or maybe that’s just a “me” problem.)

inb4 but this way the script needs less maintenance

If the Mlmym dev renames the “spacer” or “icon” classes for any reason or if he changes Mlmym’s HTML structure, this script would stop working immediately.

And anyway, running a check on every page your browser visits to determine if it is a Mlmym instance or not is simply inefficient and, I’d argue, bad practice, security-wise.