But first and foremost it's a storage item, and with all other storage items you can right-click on things to equip them, as I've already mentioned. It would be a massive oversight on the dev's part to make a storage item that's exclusively for equitable items, that you can't equip items from.
Quote from the wiki: "The Mannequin is a decorative furniture item that can be used to display armor and vanity items". It's called a decorative furniture, not a storage item. It's different than all of the other storage items, as the mannequin's interface is similar to the player's one, while all the other storage items share the same interface. I never use it as storage, as it has less space than a chest, and it only accepts equipment.
I get all that, but it's still to obvious too be an oversight, they wouldn't have made something that holds your gear, but that you can't equip your gear from.
It never bothered to me that Mannequins didn't allow you to equip things directly from their inventory. I've always seen them as a decoration more than anything. If that was an oversight, then why is it a thing from 1.1? I think that Re-logic made it this way intentionally.
They changed it in 1.4; prior to that you would place the clothing item on it rather than in it.
They would have given the possibility of equipping things directly from Mannquins in 1.4 since they were changed in hiw they work, so I think it is intentional.
