That's not how I interpret the meme. The way I understand it is rather

• we Google/Meta harvested already every source of information you share willingly with us
• actually nearly all of them, we are not actually searching through your trash
• the person is uncomfortable with this because they understand it might be a problem for their privacy, imagining anything they be might ashamed of
• in turn they ask for some kind of security
• the garbage puts a hood which absolutely changes nothing but give a false sense of privacy
• the person still willingly yet awkwardly hand away their trash, as if they learned absolutely nothing for the years, if not decades, of such practice

So I interpret this is as surveillance companies be ready to go through absolutely anything, even something literally dirty, i.e trash, in order to get yet more information about people. People knowing it's problematic and yet relinquishing even the modicum of privacy they had until then.

So... IMHO it's not about the garbage itself, rather garbage is meant as a provocative metaphor to mean literally anything and everything.