That's what a muslin is really.
It's not quite finished. It needs a zip and the hem needs slip stitching but it's done enough for me to check the fit (like all proper model shots it's pinned in the back).
It's been a good evening for sewing. After putting the muslin together I put in some more work on the baby quilt that's been hanging around for about 2 years - there are just the two short edges to finish slip stitching and then it's done.