How did they do the special effects for bạn & I???Like Harry and Zayn's special effect for example...when Harry turned around Zayn appeared.So please tell me how they did those special effects.

Oh bạn mean when they all morphed into each other.That part was amazing and I think the director and editor must have used a special type of computer to make the guy's images,I'm not really sure.And if bạn want to know what those Nữ hoàng băng giá figures of them were,they're called freeze frames.

The director and the editor must've used maybe a special computer and used their hình ảnh to make it look like they turned into each other.