This placard was likely intended to be mounted to external velcro loop on a body armor vest like a PBPV [1]. This is similar to the panel made for tactical tailor MOLLE pouches.

Inside:

Elastic loops are likely for shotgun shells or glow sticks. The compartment could also be used to store documents.

Straps:

Pouch:

Sides:

Sides have been melted to prevent fraying.