If the yolk isn't intact when it is fried, then it becomes scrambled eggs. Saying the yolk is intact is to say that it was fried and not stirred/mixed.
One problem with trying to differentiate a sunny side up fried egg and over easy/medium/well, is that if you're tagging it while it is in the middle of being cooking than they're all going to start out looking like sunny side up eggs until the egg is flipped. On the other hand, drawing a sunny side up egg is a lot easier than the alternatives, and their media frequently depicts their characters liking runny egg yolks so I wouldn't be surprised with them favoring sunny side up where the yolk is the most runny.
You can have images of a fried egg like post #4219954, which you wouldn't be able to tell if it is "sunny side up" but again it was in the middle of being cooked so we don't know what type of fried egg it was going to end up as in the end.