Nice progression of photos Alain. I've never grown conophytums, I tend to shy away from winter growers, but I admit the flowers are often nicer than those of lithops. These flowers on C. pellucidum cupreatum are particularly nice, large and bright, with just that dab of bright yellow in the center. In general, how long do the flowers last?
As I have grown more Mesembs. and less cacti the best month for flowers has become later in the year. I had over 100 plants in flower today. I like both Lithops and Conophytum flowers but Conos do have purple in their colour range and have more flowers as for the same size plant conos have more heads. Conos can be in flower over a few weeks as different heads flower. Individual flowers can fade and get scruffy but still open.