Never has a name fit a Hoya so well.  Here is a quote that I took from a Google translation from a Russian Hoya Catalog: “The name «mappigera» (mappa = cloth, -ger = to carry), refers to the morphology of the corolla, white and wide, resembling a napkin hanging from the stem. In instances herbarium wide corolla folds around the crown as the cloth hiding the diagnostic features of this taxon.”

You can see from this photo how the bloom looks just like a big napkin hanging from the plant.