Hate to be that guy and ruin everyone's fun but this is science memes, dinosaurs like that would not have there head up like that. They rarely raised there head above there shoulders.
Yeah, that classic image of tall sauropods 🦕 is probably wrong. Also like someone else mentioned they wouldve probably lowered there head anyway to vomit.
Are you talking about puking or just how they hold themselves? Because if it’s the later, have you ever been to a zoo? They clearly walk around with their necks held at like a 60-45 degree angle up from their spine. We can look up pictures of this in modern day too.
Seeing how both us and birds can vomit, probably. I imagine that developed very early. If you eat something harmful, you're dead if you can't vomit. If you don't have the brainpower to identify safe and harmful things, you're pretty screwed.
Horses are probably the single most fucked up animal on the planet, with maybe the sole exception of Przewaski's horse. Seriously we fucked them up so badly, like im pretty sure if every dog was a badly fucked up as horses they would be a hybrid of American bulldogs, Bull terriers, and chihuahuas.
This is to say never use a horse as a barometer for anything when it comes to standard functions.