Possibly. In the second picture it looks like your might be just as high as the bleeder is. Hard to tell from a picture, but if the line is actually higher than the bleeder you could have an air bubble trapped in there.
Cass would know better than I do but I'm not a fan of the calipers being run without the emergency brake cables. Some rear calipers won't adjust without the parking brake. I don't think the mustang calipers fall into that category, but I wouldn't rule out the cable being unhooked as contributing to the issue either.
