It's been too long and I'm commenting from memory.. Lenticular clouds generally form at the top of a wave, often downstream from a mountain chain, when the air is cooled and water droplets form .. some of the cloud may blow off from the wind and change the pattern a bit .. over a mountain the it may become a cap cloud and have interesting plate like forms as the winds change … and then they sometime form some really odd shapes as the winds and convection plays with them. Really rare to see a complete wave as you show and I don't see it in the original photo …. But again this is all from memory and from the long past .. ..
WhyNot
BTW haven't you noticed I don't really like subtly ....