They have good neck mobility, able to reach high up so I’d say they could hold their head above the water like a snorkel

So you see how its front legs droop so much because they’re so heavy? This means its torso is tilted far forwards and so it can’t really lift its neck much more.

But giraffes can stand on flat ground and reach their head almost straight up above them. I tried to match the body position in the comparison image I made. I’m not sure why they think the giraffe’s legs would be so far forward but it doesn’t matter because it shows neck mobility