Kim Jong Un's cane isn't just about to become the world's most scrutinized walking stick. It's also a very different crutch from the kind that North Korea has leaned on for years in constructing a myth around its founding family.

On Tuesday, North Korea's Rodong Sinmum newspaper published photos of the young leader giving field guidance at an apartment block in Pyongyang, his first public appearance in 40 days.

While...