They aren’t talking about metadata records from a photograph. I believe they are referring to information that’s included in the image itself as a banner overla

They aren’t talking about metadata records from a photograph. I believe they are referring to information that’s included in the image itself as a banner overlay. In the link, it’s the box at the bottom of the image with the date, scale, settings, etc. Each manufacturer likely has their own information they include, thus making it obvious which instrument was used. The name of the manufacturer is also included on the image. One reason why metadata like this is included in a medical/research image itself is so that it can’t be stripped unless the image is obviously cropped.