I created a dialog in main activity(the build is an xml file I styled myself)

But when I leave the app(click home button, recents button, or the call/whatsapp buttons and links i inserted in the dialog) without actually exiting the app, then go back to it through recents button, the image does not stay anymore, even though everything else does. What do I need to do to fix it so it'd stay even after I leave the app?