In short, Givaudan have just released a very special floral superpower, and it's just arrived at the lab! Hailed as a single-molecule replacement for Lilial, which has been effectively banned, Nympheal is a very welcome addition to the perfumer's toolkit. 
 
Nympheal is described by Givaudan as:
 
Nympheal™ is a diffusive floral cyclamen muguet note with green, watery and linden blossom facets. Nympheal™ imparts white floral watery density and brings a floral creaminess to the composition and high diffusivity.
 
The original 2014 patent by Kraft et al puts it more bluntly, stating that:
 
The compound of formula (I) possesses substantially similar odour characteristics and performance characteristics as Lilial...the present invention provides for a Lilial replacement based on a single compound.
 
If you have been perfuming for a while, the Lilial ban/shadow ban will have haunted you for years. If you're new to perfumery, count your lucky stars.