Super-Deformed Is Not a Separate Mode From the Story
Dragon Half constantly snaps between ordinary fantasy proportions and exaggerated super-deformed comedy. The switch is not reserved for harmless side gags. Characters can move into ridiculous visual shorthand in the middle of danger, romance or a fight and then return to normal without the story treating the change as unusual.
That visual instability is part of how the OVA tells you what kind of fantasy this is. The setting may contain kings, dragons, demon warriors and tournaments, but no amount of fantasy seriousness is protected from becoming a joke.
How you can tell
When a scene starts resembling a conventional sword-and-sorcery anime, Dragon Half often changes the drawing before it changes the plot.
Debut: Ep 001 - Mink's Voyage