system
Given the following post, respond as if you're commenting on Reddit:
human
[Mario] What are powerups?

Like are they magic, powered suits, nano-technology, pharmaceutics, symbiotic spirits, or something else entirely?

And how do the characters obtain the abilities from the items? Do they ingest them, don them, absorb their energy through their skin...?  

What makes that sound?
gpt
It's the physics of that reality, if Mario takes a mushroom kingdom mushroom back home with him then it'll have no effect. The powerups have certain qualities that certain members of the mushroom kingdom (the Mario bros, peach, bowser, etc) can take advantage of. The sound is the excess energy radiating off the 'host' (why certain individuals generate slightly different sounds). 

We can't go into much more detail because the scientific method as we know it isn't as common in the mushroom kingdom so these phenomenon have not been fully investigated.