You create a sound or an image of an object within range that lasts for the duration. See the descriptions below for the effects of each. The illusion ends if you cast this spell again.
If a creature takes a Study action to examine the sound or image, the creature can determine that it is an illusion with a successful Intelligence (Investigation) check against your spell save DC. If a creature discerns the illusion for what it is, the illusion becomes faint to the creature.
Sound. If you create a sound, its volume can range from a whisper to a scream. It can be your voice, someone else’s voice, a lion’s roar, a beating of drums, or any other sound you choose. The sound continues unabated throughout the duration, or you can make discrete sounds at different times before the spell ends.
Image. If you create an image of an object—such as a chair, muddy footprints, or a small chest—it must be no larger than a 5-foot Cube. The image can’t create sound, light, smell, or any other sensory effect. Physical interaction with the image reveals it to be an illusion, since things can pass through it.
* - (a bit of fleece)
Can I minor illusion intimidating parts of my body?
Sure, as long as they fit within a 5-foot cube. But keep in mind you can't move the illusion around.
Can I make an illusion of a rock in a five foot cube and hide in it?
Sure, if you can fit in a five-foot cube. Some larger characters might have difficulty with that, even crouched down.
Is an illusory sound only audible within a 5’ cube? A visual illusion is visible outside the 5’ cube, so I would expect a sound would be audible from more than 5’ away.
Would sunlight permeate through an illusion?