Outlook Drag&Drop mouse position is related to the whole screen.

When you drag and drop the attachment from the Outlook into the Outlook Add-in, the object gives two values:
pageX - The position is relative to the left edge of the Outlook on the web or the new Outlook on Windows client window.
pageY - The position is relative to the top edge of the Outlook on the web or the new Outlook on Windows client window.

The problem that the Add-in doesn't have the access to the Outlook width and height. So, there is no way to calculate the cursor position in the Add-in iframe to match with where the dragover cursor and trigger some particular drop area.

Why is this needed?
To create a drop area, where a user can drop the attachments, because currently the whole Add-in is a drop area which is not a good idea.