It could be a variation on a churn dash block?
Looks to me that it is simply rows of 5x5 squares and half-square triangles using 5 different fabrics.
cut 2 red squares, cut 2 blue squares fro cornerstones
cut 6 pink floral squares*, 6 black floral squares*
cut 10 yellow floral squares* (2 paired with 2 pink floral, 2 paired with 2 black floral, sew into half-square triangles)
*optionally reduce the cut floral squares by 2 and instead for each cut one rectangle the same length as 2 squares)