US 7th Army secret photo map, Operation Dragoon 1944? Info sought

[rrickoshae]

Please see the attached photos of what appears to be a photo map with annotations of a coastline. Printed by US 7th Army in June 1944 in both English and French. It is marked Secret at top right. I assume that this shows the coastline in the South of France in preparation for Operation Dragoon. It is in 2 parts, with the margins cut off so that they join together. Combined, they measure 23.25 x 33 inches. They came with a load of 8th Army News, Crusader etc news sheets.
Can anyone say how they would have been used, are they common etc etc

Many thanks

Dave