A caucasian man wearing red plaid bottoms and a black vest with large buttons with a tattoo on one arm has an upside down unicycle balancing on his mouth.
A man is holding a unicycle in a curious manner.
A man that has an upside down unicycle balancing on his mouth is holding a unicycle in a curious manner
The common way to hold any object would be with the hands. Holding an object with one's mouth, or in this case balancing an object, constitutes a curious manner of holding the object.
Balancing an unicycle on his mouth is a type of curious manner.