I'm not too sure if this has already been suggested (I'm surprised it hasn't!!) but I hope that in the Mole Market, apparel could be previewed on our own wolves, with a drop-down list of wolves' names to add the decor to, just to preview what it would look like on them!
Alternative to option presented by @Reave: Mockups w/ generic poses instead.
Addition by @Sibel: Include a place where multiple decors (excluding custom) can be viewed at once.
