Mobile OT only displays old profile pics.
You just have to clear your cache.
On Android that means going into your phone’s settings, then Apps, then Application Manager, then click on your browser, then click on Storage, then Clear Browser Cache.
I use Nova Launcher, so an app’s info page can be accessed from long pressing on the app icon.
When a new Android phone touts the ability for its launcher to do this or that, I find it worthless because I feel a huge strength of Android is being able to install custom launchers.