A man rides a black motorcycle while wearing a helmet and a van rides beside him in the distance.
A man rides a white horse while wearing a cowboy hat and a another horse rides beside him.
A man cannot be riding a horse and a motorcycle at the same time and the form of transport cannot be both clearly white as well as black.  Furthermore the man cannot be wearing both a helmet and a cowboy hat.
A black motorcycle and white horse are two different objects. A helmet is not the same as a cowboy hat. A van is not the same as a horse.
A man can't be riding a motorcycle and a horse at the same time.