Rep. Lauren Boebert has mocked philanthropist Bill Gates' wish to move toward a future in which people eat only synthetic meat—by sharing an image of a steak that a New York butcher claims was lifted from its website.
It's a Newsweek article. I understand what it means but the structure of italic part is not familiar. I think the above is overlapped sentences and the primitive form would be that was lifted from its(a butcher's) website. The problem is the isertion of whole sentence a New York butcher claims between a subject that and a verb was.
Is it possible? Yes it should be because it's an article of a global media. How is it possible? I have never seen an example like that in any English grammar books. Is it a broken sentence which is colloquial and friendly?