Not all submissions have EXIF details attached, some image manipulation software strips the EXIF unless you ask it not too. Some contributors deliberately strip the EXIF as an easy fix to portrait images appearing sideways on the site.
Where it exists you can use a browser add-on to view the EXIF or download the photo (not the smallest version when larger ones are available - the next size up will have it). In Windows right-click on the photo in question and select 'Properties' then 'Details'. On macOS, open the photo in Preview, click on 'Tools' up in the menu bar at the top then select 'Show Inspector' and click on the 'Exif' tab. In Irfanview use the 'Image information' button.