This directory is used by isomount/isorun for mounting iso images.

You can manually utilize these commands by typing from xterm :

isomount : mount iso filesystem to /mnt/iso directory; will leave open until sudo isodrop command is entered.
isorun : mounts iso filesystem, runs the autorun.sh script in iso and when done will unmount the iso
dropiso : this is lazy unload so after isorun or isodrop you might need to close xterm before all references to mnt are released.

Examples :
isorun \media\mmc2\iso-images\myrunnable.iso
isorun1 myrunnable.iso (same as isorun \media\mmc1\iso-images\myrunnable.iso)
isorun2 myrunnable.iso (same as isorun \media\mmc2\iso-images\myrunnable.iso)
sudo isomount myfile.iso
sudo isodrop

(substituting your actual iso name for the above)

This installer automatically updates the /etc/sudoers files to allow user to sudo isomount and isodrop.
If you install multiple times on a single flash you might clean out duplicates in that file.

I will probably create helper debs to install icons so that you do not have to use these commands for my (pipeline) iso apps.

If you want to make your own iso apps, it would be best if they had no libraries... just executable and data.  
If you have libraries you will probably need to install those separately to normal directories and just use iso for relocatable data and main executable.

To make your own iso files you can download isomaster from my website.  Look here :
http://wardenclyffetower.com/MaemoFiles/isoapps/