It's probably quite good for a conventional mash tun but way too coarse if you are BIAB brewing and want high efficiency. It does look like there may be some whole or nearly whole grains and you don't want that as you can't get them wet to the center and if you don't get them wet, you don't extract anything. Next time dampen the grains, leave them set for a few minutes, then mill them. That should toughen the husks so they stay whole while softening the kernels so they mill finer. You might get by with tightening the mill a little more then.