MacBook: Icons too small when wanting to attach files. How to make preview icons bigger?

Please share the trick. Whenever I want to attach files via Macbook (images, videos, etc.) to an email, whatsapp, internet site, etc., the icons become so tiny that it's impossible to really see the image. When you have several similar images, impossible to know which one to choose. Preview is not a solution, as it will deselect the already selected files. So how to go to "attaching files" modus, and still have a big icon to see exactly what file I choose?