Dropping small words is definitely something dyslexics do: they tend to jump to the meaty, content-laden words, which allows them to absorb the gist of meaning while skipping bits like articles and suffixes. Thus the oddity that comprehension, especially for 2E, is often better for more complex words or passages.
HOWEVER - kids with dyslexia usually do a lot of other weird things too, so if this is all you see, I wouldn't worry. If your child is a fast silent reader and tends to be looking ahead even while reading out loud, then some of what they speak tends to be what they remember the text saying, rather than what they are reading in the immediate moment. Result: occasional paraphrase, especially of unimportant words. (Confession: I do it myself, reading to the kids).
2E kids often don't look much like the LD descriptions you find anywhere else. I have found this forum by far the best resource for understanding what various LDs etc could look like in a gifted child. Even here, though, our kids vary wildly in how they compensate and therefore how they show their challenges, so it's worth looking at a range of experiences. Here's one thread mentioning a number of possibilities:
http://giftedissues.davidsongifted.org/BB/ubbthreads.php/topics/212491/Stealth_dyslexia.html
