Only a limited portion of the "About" section and small, non-expandable versions of profile/cover photos remain public.
Facebook’s locked profile is a privacy setting designed to protect users—especially in countries where online safety is a concern. Only people on the locked profile’s friends list can see full posts, photos, and details. facebook locked profile viewer online
Several online "viewers" claim to bypass these restrictions. Most of these tools rely on or publicly available metadata rather than actually "breaking" into a locked account. Only a limited portion of the "About" section