The Cloak of Many Fashions is found in Xanathar's Guide to Everything and says:
While wearing this cloak, you can use a bonus action to change the style, color, and apparent quality of the garment. The cloak's weight doesn't change. Regardless of its appearance, the cloak can't be anything but a cloak. Although it can duplicate the appearance of other magic cloaks, it doesn't gain their magical properties.
My question is does the actual physical shape of the cloak change, or is it entirely an illusion? The description mostly seems to imply to me the former, except for the line where the cloak's weight doesn't change. If I for example changed a cloak made of lace into one made of cloth of gold its weight should absolutely change. That it explicitly doesn't implies illusion.
On the other hand, there are definitely spells and enchantments that change the size of an object without changing its weight. The Pole of Collapsing, also from Xanathar's Guide to Everything, explicitly physically changes a 10-foot pole to a 1-foot-long rod without changing its weight.
On the gripping hand, the line 'regardless of its appearance, the cloak can't be anything but a cloak' seems to imply that it can appear to be other things but remains physically a cloak. Or that could be taken to mean that you can change its appearance however you like as long as it remains a cloak.
What say you?