ELI5: How does media storage from WhatsApp work?

I've noticed my device's storage has both videos from WhatsApp said to be taking up storage,

And the WhatsApp app is seperately taking up significant storage space as well. From what it seems,

It seems like the main bit of it is media, too.

So, can it be concluded that media from WhatsApp is stored on phones twice?

I tried chatting with the support AI to find an answer to my question and the ones that came after, but even it addmited to having made several mistakes throughout my chat with it.

So how exactly does media storage from WhatsApp work?

Thanks in advance