There are two answers.

UNDER CURRENT REGULATIONS (and the injunctions stemming from them), if you have stills or embedded videos on your page provided to you by another sponsor, you can provide a proper 2257 statement with a reference to the primary producer's information.

UNDER THE REGULATIONS OF THE ADAM WALSH ACT, which is pending publications of final regs, you will have to have full 2257 records yourself, including crossreferencing, of any content (embedded videos, sponsor-provided stills, etc) that appears on your site (specifically, appears displayed on a page where a URL you own is at the top.

No one knows when the AWA regs wil be published. The proposed regs were published several months ago, so it's possible they could publish any day, or not for 6 months or more. Our general approach is to assume that we will need to be compliant with the more restrictive regs.