Steps to reproduce:

• create Phriction document with visibility set to everyone (no login required)
• set default view policy of Files to "logged in users"
• create document containing

dot {{{
digraph G {
thing1 -> thing2
}
}}}

Expected results:
non logged in users can see graph

Actual results:
non logged in users see broken picture

I suspect this generalizes to other policy default differences as well