I don't know if MBRs seen in the pix show any sort of institutionalized attempt to use such rifles in the DMR role, although the altogether too-highly-mounted scopes suggest the possibility.  Who knows?  Might be simply an attempt to re-purpose "donated" or captured weapons without any sort of DMR program.  Might as well put every firearm to use, right?  

Even if the "troops" in the pix were issued scoped MBRs in a DMR-type role, there is no guarantee that there is the individual training and/or the organizational capability of using them, effectively as such.

The US mil has come to see the benefits of a DMR, and has instituted various programs to integrate a DMR into the lower tactical levels.  More modern firearms are now employed than the stop-gap M-14.  Time will tell if the knowledge is institutionalized.  After all, the US Mil has purposely discontinued sniper training at various points over the decades.

In short, I would be hesitant to draw any firm conclusions from this particular set of pix.  As time goes by, and such things show up consistently, then that would require an re-evaluation.  

I would think it essential that US troops down to the lowest level be informed that their opponents have possible DMR capability, and to conduct themselves  accordingly.  No sense in ignoring a possible threat.

All of the above can be reduced, or even eliminated through the use of the proper equipment and fieldcraft.  That said, a good deal of the concerns voiced are dependent on the length of the barrel of the major caliber weapon.  Most DMR rifles have rather longer barrels, which serves to reduce the DMR rifle's visible signature, assuming proper fieldcraft.  For military with advanced technology and adequate support for same, that can include sound suppressors as well as advanced muzzle devices, which can reduce muzzle/optics displacement while also reducing enemy-perceived sound/visual signature.  There are any number of ways to skin the cat, as long as one has the technology/support to do so.  I doubt that most of our likely opponents have that capability at the present, but I would not be surprised to find that [I[some[/I] select units were provisioned and trained to high standards.  Our troops certainly should be warned about this situation, and warned to conduct themselves accordingly.

None of which the subjects of the photos have.

Spilling a canteen in front of one's muzzle, or spreading a blanket don't show much in these pix.  Pretty simple stuff, and a lot of Photographers might miss that very useful bit of intel.

They are poking their barrels out of window and you think they are going to pour what little water they have on the ground so as not to give their position away?

Well, I don't say these guys have quality training.