This is the main attraction as it lets you store images in small file-sizes.

Create an image use the dimensions 128 x 64 (The program should be able to handle smaller dimensions). The export it to PNG or JPEG. Using Image Magick convert the image to a CCITT Group 4 compressed image. Use the following command:

magick example.png -monochrome -compress Group4 example.tiff  

Then using the ccittconvert.py script in the ccitt folder you strip the file of all metadata and output it in a .bin file. Make use of the following command:

python ./ccitt/ccittconvert.py example.tiff example.bin  

Note: the script can also take a single argument, outputted file having the same name as the inputted file
The resulting file can then be made into a hexadecimal string using the following command:

echo $(hexdump -ve '1/1 "%.2X"' example.bin)

Note: the previous command may output something different on macOS and does not work on Windows' CMD or PowerShell

Download the ccittdriver.py from here or make it using the ccitt-driver-release.sh (for Linux / macOS with GNU sed only)
Plug-in your fx-9860G in USB Flash Mode. Copy the ccitt folder to the calculator (ccittconvert.py, ccitt-driver-release.sh, ccittdriverdev.py can be omitted). Copy the ccittdriver.py file in the folder as well.
Create an empty file called images.py in the same folder. Add the following into the file:

your_image_name = "hexadecimal_string_output_here"  

Edit the ccittdriver.py file, replacing the your_image_name with the name of the image input into the previous file. You should now have a file structure like this:

ROOT  
└── ccitt  
    ├── bitbuffer.py  
    ├── ccittcodes.py  
    ├── ccittdecoder.py  
    ├── ccittdriver.py  
    ├── ccittmodes.py  
    ├── image.py  
    └── modecodes.py  

Now running the ccittdriver.py calculator should display your image (give a take a few tens of seconds). Note: the calculator might throw a MemoryError message if the image is too large