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iMore Question When I unlock the lock and then click on guest user & then the picture, nothing happens. I've tried dragging a picture as well, still nothing. What else can I do? I'm using Sierra.
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The "guest user" option is specifically for just that... a guest user. I haven't tried it but I'm going to assume that in order to change the image you would have to log in as that guest user in order to do so. But even when you/they log out, their information isn't stored.