Do you have the PDF Annotation Feedback module enabled (https://docs.moodle.org/403/en/Assignment_settings#Feedback_types), with an appropriate document converter (https://docs.moodle.org/403/en/Document_converters) enabled?
If you did, you should get an in-line version to the left of this view, which is markup-able(?) but also serves as a view of their submitted work.
However bear in mind the source (less of an issue in this case if it's an image) goes through a conversion so the result may be different from the input.
If you did, you should get an in-line version to the left of this view, which is markup-able(?) but also serves as a view of their submitted work.
However bear in mind the source (less of an issue in this case if it's an image) goes through a conversion so the result may be different from the input.