Here you see a highspeed videoclip of a female singer singing ornamentation in Neutral.
You can see the progressive narrowing of the supra glottis structure with the modes Neutral. There is no gap between the vocal folds, and you can see that the posterior pharyngeal wall behind the larynx and hypopharynx is relaxed leaving the area open. The vocal folds can be seen easily as the false cords are retracted and the aryepiglottic folds are stretched more so they become thinner creating a funnel shape which is slightly steep.
Notice also the movement from the vocal tract producing the grid, which is the foundation of the ornamentations. The grid makes it possible to achieve an even and equal rapid run of notes.