I have the same question.
As per USCIS website the required documentation is
1. A copy of your last EAD (front and back). .
2. 2 photos with a white background taken no earlier than 30
3. A copy of Form I-94 Departure Record (front and back)
4. Pending I-485 receipt notice
But so many times in this form I saw "Color copy of your driver’s license" also to be attached.
Were there RFEs asking for this or is this a precautionary step?
-------they will send RFE if you dont send "Color copy of your driver’s license" and first page of your passport that has your photo, DOB, name
Thanks for the time and reply