If you have a logo or some other custom icons that you have uploaded in the 'Shared Components' of the application, there is an easy way to include these with your application export, so they will be automatically imported when you install your app elsewhere.
1) Export the Script file for your image.
Navigate to Shared Components > Images > [YourImageName].
You will see on the right hand side an option to display the install file script.
Click on the 'Display Install File Script' link and it will open up the script text in a new window.
Copy this text to your notepad or save it as a file.
2) Create an Installation Script
Navigate to [YourApplication] > Supporting Objects > Installation Scripts.
Click the 'Create' button to create a new script.
In my case, I am going to create one from scratch, but you can also create from a saved file.
Give your script a name - you are able to put the SQL from a number of images in the one script file.
The paste the script that you copied from step 1. Click Apply Changes.
3) Exporting and Importing Applications
When you go to export your application, make sure the option Export Supporting Object Definitions is set to 'Yes'.
Also, when you import your application, there is an option to Install Supporting Objects. Also make sure this is set to 'Yes'