Hrmmm…(Translate: How do I make this Emerald into a Leather Cap?)

..... its litteraly trading bro..... he is not turning emeralds into leather helm

Then How did Villagers get Leather from Emeralds while getting Trapped in a Box

Did you knew that villagers have an inventory ?

They can only Pick Up Crops and Bread, Not actual Leather, They don't even Kill Mobs, which is the Only Way to Get Leather