You have apparently inserted the pictures "by reference". This action stores the path to the original file instead of the actual file.
When you save the file to your stick and open it on another computer, the saved path no longer works.
You'll have to come up with a method where the file path works on both computers or store the actual pictures instead of storing them by reference.
how do I do that?
That depends on your computers (mac or windows?, are they on a network? )
One option that may or may not work is to:
a) move the files to your stick
b) Re-insert the images by reference from their new location
c) make sure that when you mount the stick on the second computer, it has the same name/drive letter as it does on the first.
If both computers are on a network, you could also move the files to a shared directory that both computers can access. Make sure both computers mount this directory using the same drive letter (windows) or name (mac).