Hi Danny - yup that's a bug, thanks for reporting it!

Technically the 3D viewport with a parallel view set is an orthographic projection, but really that "ortho only" there was intended to mean "Top, Front, Right views".

You may run across a few similar lingering bugs like this where the code assumes that a view that is not perspective is one of the Top/Front/Right views, which used to be the case before the parallel view mode for the 3D view was added.

It's a very simple fix, but there are 2 choices that I have for what should happen.

One way I can set it up is so that when that option is enabled, the image will not show up at all in the 3D view in any circumstances.

The other option is that I can make it show up in any "Plan ortho view", which would include showing it in the 3D view when that was set to a Parallel projection and it was looking straight down on the construction plane like the Top view.

Do you have any preference for one behavior over the other?

- Michael