Display image not working on Android device

I follow, step by step, the tutorial My First App (Ionic/Angular). On the server, I can take many pictures and all of them are displayed on the screen. Good …
On Android device, I can take pictures, but only a little square is displayed on the screen. A square for each image. If I close the app and re-run it, I see as many squares as images taken.

Have you an good idea for fix this problem ?