Some logos are created for letterhead and are quite long. Shrinking them to fit on a left chest will make the lettering too small. These long logos sometimes need to be changed so the words in the logo are split up and stacked.
For example a company name of Erickson, Smith and Schultz Engineering and Manufacturing would be a very long name to embroider on a left chest.
You can suggest that the logo have Erickson, Smith and Schultz on the top with Engineering and Manufacturing on the bottom line. The letters can then be larger and more embroidery friendly. The name all on one line would either result in a design that is too wide for a left chest or lettering that is too small to stitch.