not Captain Marvel on this occasion

- 'Marvering' in the glass making sense indicates that the original gob from the glory hole was picked up on the blowing iron - and here is Harold Newman's explanation ('An Illustrated Dictionary Of Glass') of the word marver ...…...…….
""A polished iron or marble table upon which molten glass, gathered on the end of an iron tube (Blow-Pipe) or rod (Pontil), is rolled into a globular or cylindrical symmetrical mass. The process is known as 'marvering'. As the 'paraison'
(gob/gather/bubble) is very much cooler than when it was first attached to the blow-pipe or the pontil, it does not adhere to the marver.""
words in italics are mine.
I'd suggest the word trailing - applying threading or thin trails of glass to a body - should be confined to additional work after the body is cool, and is seen as external ornament, rather than as this piece appears.
IMHO, decoration on the vases here was marvered/rolled into the bodies whilst both the bodies, and this additional colouring, were plastic - thus the marvering forced the colours into the body, such that they are never proud of the surface of the vase - possibly then the vases were blown.