Don't you have a bigger version of that picture, where you can actually see the details?

Nope.

Its a strange weapon, remove the totally out of character (for the series) barrel and you have the light machine gun from New Vegas......I can see the logic of one of the arms manufacturers taking a existing light machine gun design probably in use with the national guard and non-powered armor troops and modifying it to take advantage of National Guard Powered Armors capabilities giving the NG Power Armor troopers a weapon (that while over heavy for a regular design) that could be used as a heavy rifle or a light machine gun respectably.

Really though, aside from coming up with a conventional specialist rifle for the Power Armor units I cannot see a reason for the rifle being used instead of the Fallout 3 rifle designs which I found much more useful and superior assault rifle designs.....looks wise I feel the combat rifle looks more like it was built for power armor units, althrough again the calibre for that is weird since you would think it was firing a large calibre than a pistol round.

Dunno if it is just my browser, but the link only gave the thumbnail... Found the original picture on the Wikia site. I maintain that they should rather have labelled it 'heavy rifle' or something, and then kept 'assault rifle' either for the AK-47 style rifle whose meshe supposedly is in-game (pretty much similar to the Chinese AR from Fo3) or for a G3-style assault rifle a la Fo3.

Oh sorry, I didn't understand the problem, as my browser showed it in full size (my phone's browser shows the link's image as a thumbnail though).

But yeah, I agree.