DrKalinka said: Nerd alert: The delta ring does not work that way. The rail can't pass through it. It has to go over it. The rails also look wrong. The fire selector doesn't make sense.
At any rate it is a better representation of what rifles usually are depicted as, but if you are aiming for realism, why only go halfway?
I-Operate-Firearms-for-a-Living alert:
The rails look fine; nothing wrong that can't be attributed to the limitations of the medium. You literally answered your own criticism with rails that 'have to go over' the delta ring. Daniel Defense makes a few; using the delta ring and still keeping a continuous top rail to the front sight post. The selector switch (your 'fire selector') looks fine too; if there is any gripe to be made about the lower receiver is very slightly too narrow; which might be why you think the selector switch looks off; it looks like there is too little space to put it into semi-auto. this is also why the lower bit of the bolt catch and release is just not there; it would have been drawn over the back end of the magazine release; or the very odd looking lack of a hinge on the trigger guard.
That being said, there is something on the weapon that would prevent its ability to operate: just below and forward of the ACOG, there is an indentation on the upper receiver. It should be a protrusion, of the same dimensions. Inside the weapon is a bolt carrier group, which carries the bolt and firing pin; and has a cam that runs through a kind of track that runs trough the top of the inside of the upper receiver. The track twists at the end to lock the bolt in battery, and passes through the area that this weapon has an indentation; which means that this rifle cannot send its bolt carrier group all the way forward. Which means it can't shoot.
That is just looking at the weapon; this doesn't even begin to criticize the issues with the woman herself; such as a total lack of appropriate gear (useless eye-pro, not so much as a trauma plate, no ammo) or the suspiciously immaculate manicure she's sporting that you never see in a war zone. This image is very much not going for the level of detail you seem to be trying to assign it. Its just a drawing, not a photo.
The rifle is not 'so' wrong. If all you are is a nerd, check with a professional before you make an ass of yourself, even just on the internet. (If you're a Call of Duty nerd, best not to say anything at all, ever)