I've searched around trying to determine the problem here but have and no success so I decided to ask here in the assignment forum.
I have a teacher who has students upload image files via the assignment module. JPEG files display inline without issue so he can grade the submissions online with ease. PNG files, however, do not display inline...which seems odd given the fact that they display without issue in other areas on the site (theme images for example).
Is there a reason why PNG do not display when submitted as an assignment?
Thanks in advance for any information that can be provided.