Where are people getting that he has a twin brother

There was a photograph in one of the earlier chapters showing the two brothers wide by side. They looked identical safe for the moles. ML has 2: one on the right side of his chin and one under his left eye. His brother has one mole on the left side of his chin

i think its the other way around though; se o in's beauty marks are on left side of the chin & under his right eye. while the brother's mark is on the right side of the chin