The pattern is based on a simple technique of snowballing 2 corners of a fabric square. Many patterns use this technique, but in this case, the simplistic design of letting the fabrics be the showcase really makes the most impact.
How to Make a Snowball Quilt Block
A snowballed quilt block is constructed of 1 larger square of fabric and other smaller squares (usually 2 or 4 squares). This is such a beginner-friendly quilt technique block. There are so many options and possible combinations!