I tried Template Debugging | Hugo advice of putting {{ printf "%#v" . }} but it just shows some useless stuff like resource.Resources{(*resources.resourceAdapter)(0xc00007d360), (*resources.resourceAdapter)(0xc00007d450)}
That issue will be closed as a double issue quite soon. There are plenty of them open with explanation that it’s hard to “debug” functions and methods. Get back here when that happens.
The documentation isn’t enough.
It’s open source. Help extending it. Add an entry for .Exif on the list and link to it’s subdocumentation.
You could use debugprint to debug something like $image.Exif instead of a dot.