Not really. From a height standpoint maybe, that all depends on where people position their bars, - which varies quite a bit. Some might be higher, some might be lower.

With your hands on your flat bars where the shifters are, you tend to bend your elbows out to the sides, - which increases your frontal area and drag. The same is true when somebody is riding on the tops with drops. But on drop bars if you have your hands on the hoods or in the drops, your elbows bend downwards allowing your arms to stay tucked.

I should qualify the above to say that it's harder to keep your elbows bent downward vs outward when on the tops. It's certainly possible. I think what most people do when riding on tops or on flats is to not bend their elbows much at all, which makes them sit more upright.