It's broken in two ways, it's not hyper-linked nor is it updated to satanisgod.org
https://www.satanisgod.org/www.angelfire.com/empire/serpentis666/Biffrons_23952.gif
Copy, paste it to your URL address bar and out comes the Sigil.
There are also other links broken in JoS mainsite but it's okay I'm sure when the website is updated sometime this year hopefully things are improved.
According to Maxine besides the Astral grid ritual(anti-enemy grid ritual), there would also be an update to JoS mainsite.