Nobody can access and even less see the pictures on your GDrive if you haven't made them public

Anyway

It is obvious that the device has some launcher in it (you wrote the loader) or Shell Unlocker. Whether it's in the internal memory or on the card (it would be easier to manipulate).
Software locations are usually set in ini files. You have to access them (from PC), examine them, find the right one and enter the required path in it. Of course, you have to put all the necessary software and content on the card
This was mentioned in the thread I linked to you in my previous post