Andoid can't select existing photos.

I am using this form for a photo submission contest.

It works fine in desktop and iPhones but in Android, users can't select existing photos - only the camera, camcorder, or google drive files.

Try clicking the "Documents" and browse the folder which contains the photos. 

Let us know how it goes.

Turns out it does work. My system defaults to a list of files in my drive.

Here is the default view after clicking on files:

Only when I click on the hamburger menu do I see the option for photos.

I am guessing this is a system setting and nothing you can control.

Yes I believe so since we have different views on each device. It would also matter what image apps are installed on your phone..