The mobile site vs the app.
So on the mobile site if I try to upload a picture, it shows as if it was an app....straight to the gallery. Yet, the mobile app shows the file manager, as a website would.
The second picture is what I get in the mobile website, which is mostly how it would look on a native app. Which is great. The first one is what I get when using the mobile app, which is mostly what you get when you go to a site on chrome. That's a little contradictory. 😔😔😔😔🤔 PLEASE CHECK the attached video
This is simply because your browser in Android is already linked to Images gallery as a default app servicing image uploads. Android asks about your preference the first time you try to use this routine and then remembers your choice.
UNA app would be treated as a separate app, not a website within browser, so Android needs to ask what do you want to use as a file service for image upload for this app - it should only do it once. In most cases it won't do it at all, since most people only have the default Images app to supply image uploads.
While the mobile site seems sleeker the app gives more options. As Andrew was saying sometimes your default app you use to upload pictures doesn't always have ALL your pictures. Gallery, Google Drive, Google pictures, Picasso etc can host many pictures but not all of them in the same place. Your gallery may not have a picture you want to upload because a picture you like may be in Dropbox or somewhere else. So there is some benefit to having to choose the app you want to upload the picture from.