Diamond With A Dot
This is a figure with a small dot or diamond in the center, which is common in kaleidoscope. This emoji looks a bit like a snowflake, which is usually used to mean "lovely", "interesting" and "colorful".
Different platforms depict different icons. In terms of color, most platforms depict blue icons, while Docomo and Softbank platforms depict purple; As for the color of the center, there are many kinds, including blue, yellow, red, purple and white.
In terms of shape, except the patterns depicted by Docomo platform, which are similar to flowers and have four petals, the figures depicted by other platforms are basically rhombic or similar to rhombic.