Sort of new here -

The items in the restocking "main shops" never seem to show item details when moused over. While items in the more "special" shops, show a small pop up box with details and image of what it would look like if its wearable in the wardrobe.

Is there a preference setting or something, in order to get the main restocking shops to show these details as well?

Nope, the stuff in the main shops doesn't give you an infobox because it'd make it too easy to find valuable items to resell in the user shops

Ahhh got it!

Thank you for helping on this.