Makes sense to me.
Posted under General
There might be a zipper but with it not visible. That's pretty easy to imagine, really. Zippers aren't particularly large necessarily, and often there are often flanges on the things that are attached by the zipper, expressly for the purpose of hiding the zipper. In such a case, I don't think the post should be tagged zipper, even if the garment is half-unfastened in a manner that suggests a zipper is holding together the other half of it.