The tool was made with python and it imported several libraries: os, shutil, tkinter (GUI), and PIL (Python Imaging Library). The source code is only 32KB. It jumped up in size when converted to an executable file using pyinstaller. The executable file allows the program run without having the python interpreter or libraries installed on the user's local machine.
You bring up a good point, reducing the size by parsing library files and using pyinstaller options will be something to improve the tool in the future.