I was wondering that
@Celia but now that I have the pattern I can tell you that the whole thing is pieced. The rosettes are actually relatively simple - 6 petals, and 6 smaller pieces in the junctions (leaves, maybe).
The one in the picture has been done with fussy cutting of patterned fabrics, so it looks far more complicated than it is. I may do that with some of the blocks, but not all of them - apart from anything else it would take a vast amount of fabric to do that for all of them. I will take a photo of my fabric later today - I could do with some ideas for the background colour too.