Strange. I just reviewed my Recents on the web version and I only get blue boxes and pink dots, no photo at all. What version of the App are you using? Maybe someone using that App can duplicate your experience.
I have the generic silhouettes on my phone both in the android Family Tree app (4.6.9) and in the browser (Chrome)
Android 4.6.9 on my tablet - photos where I have photos; generic pink and blue heads where I don't. You can clear your cache in the app to force a fresh reload.