The Gallery apps starts up with a black screen, before it draws the app itself. This leads to a flashing/jarring first-open experience. Opening many other apps on Android, I notice they start with a white screen.

(I tested Play Store, Play Music, Android Pay, calculator. They all start with an initial white screen. Drive app starts with a white screen with a static logo. Note: the clock starts blue, but ends with blue so there's no flash. Keep starts with gray, but ends with gray so there's no flash. So many the app can pick which initial color it fills with?)