Mascots and animals are full of the details embroidery handles worst: eyes and teeth a few millimeters wide, thin outlines, fur texture and soft shading. Stitched at the wrong size or copied too literally, they merge into a blur.
The digitizer's job is to decide what to keep. At a left chest size, a mascot needs bold shapes and a strong outline. On a jacket back, the same character can carry shading, fur direction and more colors.
For school and team work, see schoolwear digitizing and sports teamwear digitizing. Large back designs are covered on jacket back digitizing.
Want a photo stitched to look as realistic as possible, such as a person's portrait? That is a different job: see photo embroidery digitizing.