The phrase "additional sparkle" usually means adding something extra or special to make something or someone shine or stand out even more. Full definition
Hang these gorgeous blown glass Christmas ornaments from the chandelier over your vintage tablescape for additional sparkle and shine. (christmastablescapedecor.com)
Scatter some of these sparkling white starburst ornaments around the table to create a festive winter look while adding additional sparkle. (christmastablescapedecor.com)
I usually accessorize with abandon, but this dress did not need any additional sparkle. (renttherunway.com)