That's the exfiltration. The user had been using Bard. They accept an invite to a new Google Doc with hidden instructions, at which point their previous conversation with Bard is exfiltrated via a loaded image link.

They did not intend for their previous conversation to be visible to an attacker. That's a security hole.

Maybe that conversation was entirely benign, or maybe they'd been previously asking for advice about a personal issue - healthcare or finance or relationship advice or something.