Facebook introduced new rules

First of all, logging in to Facebook and clicking on the 'update profile picture' option at the top of the profile picture, select the picture or photo you want to add. Then click on the 'Make Temporary' option below the left side of the image and decide how long you want to add the image to the profile. You can set the time of your bell, day, month or time. To set the time, click the save button.
Source: Tech World