How to Change Login Pic for Other
In Mac OS, when you have your login screen configured to show a list of users (as opposed to a username/password text box combo), each user is accompanied by a large circular image. This is alternately known as a 'User Picture' or a 'Login Picture'. All users have such an image even if they are the generic gray silhouette image.
Furthermore, when you enable network users to log into your mac, and have the login screen configured to show a list of users, the User Pic that accompanies the 'Other...' user is a special login picture, which is a gray silhouette of three individuals, like so:
I would like to change this image so that I can have a more fun picture for the students in my school to click on when they want to login with their network account. I do not know how to do this.
One idea I had, and it was admittedly something of a brute force idea, was to find that image on the hard drive and replace it with a picture of my choice. The image seems to be this one:
/System/Library/CoreServices/CoreTypes.bundle/Content/Resources/Everyone.icns
However, overwriting that file with a normal image had no effect on the login screen, so I am thinking that either, 1. that isn't really the file being used, or 2. it is the correct file but something else needs to change in addition to over writing it with a different image.
To clarify: I am solid on changing the user picture for normal users and I have a script in place already to do so. I do not need help with that. It is the 'Everyone' image, or the gray silhouette of three heads, that accompanies the 'Other...' prompt on the login screen that I would like to change.
The "Bounty Goal" is to replace the 'everyone' image on the login screen with one of my choosing. This is not the same thing as providing a login pic for an individual who has signed in by clicking on the Other link. Thanks in advance for solving this!!
One possible explanation for the lack of success so far may be that if FileVault is enabled, the system is booting from the EFI partition,(because the main drive has not yet been unlocked).
In previous OS versions, the login screen's resources are obtained from the Recovery partition, though I mounted mine on Mohave and couldn't see anything relevant.
https://superuser.com/questions/362788/how-do-i-change-the-filevault-login-icon-on-osx-lion/364587#364587
As it turns out, replacing the login icon for the 'Other...' prompt on the login screen is as simple as:
Disable SIP.
Overwrite this file with any image of your choosing that is 72x72 pixels
/System/Library/PrivateFrameworks/LoginUIKit.framework/Versions/Current/Frameworks/LoginUICore.framework/Resources/OtherUser.png