On very rare occasions a flower appears with what is best described as a malformed flower growing inside another flower. Known as Vegetative Centres they occur rarely but at some time in a rose grower’s life may cause a gardener concern.
Several varieties are known to produce this effect constantly and seen more commonly on roses which have been fertilised heavily.
If the variety is known for this effect there is nothing that can be done as it is in the genetics of the plant, however if it only occurs on rare occasions cut off affected flowers and reduce how much fertiliser used.
Next flowering may be normal.