From looking at the glance API reference docs, it looks like /v1/ or /v2/ is always required in a request, so the fact that nova returns an unversioned '/images/{image_id}' URL in the location header makes me think this all predated the split of glance from nova, unless you can configure things in your cloud to alias /images to /v1/images or /v2/images but I'm not sure if anyone does that.
From looking at the glance API reference docs, it looks like /v1/ or /v2/ is always required in a request, so the fact that nova returns an unversioned '/images/ {image_ id}' URL in the location header makes me think this all predated the split of glance from nova, unless you can configure things in your cloud to alias /images to /v1/images or /v2/images but I'm not sure if anyone does that.