You are reading the documentation for an older Pickit release (2.0). Documentation for the latest release (3.3) can be found here.
Maximum angle between pick frame Z-axis and surface normal
This setting becomes visible whenever an alignment is enforced(add link). With this setting, you can specify the maximum angular difference between the Z axis of your adapted pick frame and the original pick frame. As seen in the image below, if the new frame is tilted more than the maximum specified angle, the object will be labeled as unpickable and not sent to the robot. In the Pickit web interface, unpickable objects are displayed orange in the Objects view and the Detection grid.