Open the file in CloudCompare and click on one of the scans contained in the file.
If the file has normals, you will see the entry ‘Normals’ in the properties table of the CC Object section and a check box to control visibility.
If this option is not visible, it means the file does not have normals.
Alternatively:
Extract the XML portion of the .e57 file using the utility e57xmldump available here.
If the file has normals, you will see information about the normals for each scan position in the XML.
Normals are perpendicular to the tangent plane line at a particular point on the surface. They yield especially useful information about a curved surface's characteristics but conversely can tell us much about the planarity of a flat or angular surface also. Normals can tell us the rate of change of curvature when a surface has an angular departure and tell us just how perfectly flat something is.