The bridge only transforms images attached to events to new media proxy links.

If a bridged matrix user joins a channel, as IRC client I see the following information:

    justJanne[m]!justjannem@Snoonet-han4h7.720l.ak1n.m0s0nj.IP (@justjanne:matrix.org)

With the mxid I can call /_matrix/client/r0/profile/{name}/avatar_url and get the mxc url.

    mxc://matrix.org/uQMYcfRtSKFlYYBXLGhuIXzq

In the past that was enough, I could just call /_matrix/media/r0/download/.

With authenticated media, I would need to get a URL with a signed JWT from the bridge's media proxy such as

    https://matrix.org/snoonet/media/v1/media/download/ARahZwUoMu0BcC8Di6Q3N3lpPAejecpE6OyRcKnsvw3n7pjmP7XVSXG8hYT99knbOtESJ9ODlzqLcdLy8Y2mPs9CeTshGEPwAG1hdHJpeC5vcmcvdVFNWWNmUnRTS0ZsWVlCWExHaHVJWHpx

But what endpoint would I call to get that? From what I can tell there's no way to get the bridge to give me a users' avatar.

I'd expect to have an special endpoint such as /snoonet/avatar/{mxid} that'd redirect me to the /snoonet/media/v1/media/download URL.