I understand:

All 32 files were marked as clean by you
All 32 files were added to the Cleanset
The ‘digital signature’ is issued by the creator, in my case, Gravis Marketing!

What you are ‘not’ being clear about is:

How were all 32 files signed with the ‘same digital signature’ when the other 31 files submitted by others were not Gravis Marketing-related but were different creators!

By ‘same digital signature,’ do you mean that the other 31 files were also IDP? If so, the creators of the other 31 files would ‘still’ be different so the digital signature would be different.