The External pockets are a small dry bag , to put on the end of the bag, where the reflective patch is,
so, they have a reflective patch on them.
http://www.ortliebusa.com/prod-76.htm So, There is a roll and snap closure to cope with..

Currently , there is an Internal pocket, that lays against the stiffener panel .. the 'Put-In',
when they are offered for retro fitting prior bags..

the Internal pockets are now standard, the external one is aftermarket.

Bike Packer Plus has an external Outside pocket.. outer face .. included .