gphoto2 --manual describes how to switch camera control mode.
When camera control is off, modprobe sd-mod; modprobe usb-storage allows the camera flash to be mounted in the filesystem, often from the device /dev/sda1
When camera control is on, gphoto2 can be used to control the camera more extensively.
An image from the camera can be used as a template for faking in GIMP. It can then be recombined with a header from the camera's saved tiff's for upload to the camera memory, such that the camera can be used as a portable image viewer.
# image is 9437184 header is 14409 dd if=P1010001.TIF of=P1010002.TIF bs=14409 count=1 dd if=gimp.tif of=P1010002.TIF skip=8 seek=14409 bs=1 count=9437184