(No pattern) So cute. I see it's a 9-patch. If I were to use 5x5 charms, I'd cut a colored charm into 4 pieces vertically and horizontally to make 4 2.5" blocks. Then take a white square and sew two of the little squares diagonally in 2 corners.
"Random Vector" quilt by Susan of SKquiltlabs. This quilt is laid out according to a random number generator for pattern orientation, and the maker tried not to repeat a color in any row/column - such precision and planning for something so seemingly "random." Wow!