I don't agree that it's a mislabeled iris. Schreiner's juices their catalog pictures to such an extent that you often can't rely on them for identification. Their registry descriptions are also sometimes less than precise. The picture uploaded by
@Bitoftrouble looks pretty similar to other images of Pop the Question I've been able to find online.
On the other hand, I'm not sure about the picture uploaded by
@EllenTN . The differences could just be a result of lighting and/or weather, blended irises like that do tend to be a bit variable. Don't know.