The coronal cavity at 11 o'clock does not display the prominence on this 17.1 nm wavelength image.
The connection of a prominence to lower layers looks like a "stalk" at 17.1 nm, but the length of the prominence does not show at this wavelength. Sticks or "stalks" are common on the face of the sun at 17.1nm, but curently the author has not proved they are always the connection of a prominence, for lack of simultaneous H alpha images.
Next Day: The top right prominence (which is not on this magnified stereoscopic picture) has erupted out of its magnetic cavity.