3828446 - What is the difference between Receipt Required and Receipt Image Required?

I am trying to set up an Audit Rule that prevents an expense report from being submitted if the required receipt(s) are not attached, and would like to know the difference between "Receipt Required" and "Receipt Image Required".

While creating the conditions for an audit rule, there are two similar values for the receipt requirement: Entry - Receipt Required and Entry - Receipt Image Required. , KBA , CON-EXP-ADM-MOP , Monitor Payees , CON-EXP-ADM-AUR , Audit Rules , Problem