Multiple featured images on search engines

A client of mine wants multiple featured images pulled through on Google. We have already got them to page 1 for their target key terms, but we want to claim more real estate by having more than one image, like the competitor above them in the attached image, show up.

They are on 7.0 - we thought this could be why, but competitors are on 7.0 and still have multiple images pulling through.

Any recommendations would be fantastic thank you 👍

have you figured out how to do that? thank you