Do they come up at all when you vacuum , I agree if this is roll marks they might never come out try a stiff brush on then to see if you can make the nap stand up.

Roll crush marks do not indicate a flaw in the carpet. These marks usually disappear once the carpet has fully acclimated to the humidity of its new environment, typically within six months of installation.

How was this rug made and from what material? They are most likely from the rug being rolled up for an extended period of time. It may also be the light. If it is hand knotted wool, the light reflects differently on each side of each individual yarn.