Okay so read these two passages:
"And out of the west there would be at times a great cloud in the evening, shaped as it were an eagle, with pinions spread to the north and the south; and slowly it would loom up, blotting out the sunset, and then uttermost night would fall upon Númenor."
"And some of the eagles bore lightning beneath their wings, and thunder echoed between sea and cloud."
Are they eagles or are they clouds?
Now these:
“The Balrog reached the bridge. Gandalf stood in the middle of the span, leaning on the staff in his left hand, but in his other hand Glamdring gleamed, cold and white. His enemy halted again, facing him, and the shadow about it reached out like two vast wings."
"It stepped forward slowly onto the bridge, and suddenly it drew itself up to a great height, and its wings were spread from wall to wall"
Is it the balrog's shadow that LOOKS like wings, or is it wings?
This is something tolkien does, several times, and it's always meant to represent something as something else, it is SIMILE. Homeboy is just trying to be fancy with his descriptions.