Docs say

If these contain complex data structures, it may produce false-negatives for deeper differences

By false negative does it mean when React will say that "do not re render" while it should? If yes, can someone bring example why a complex data structure could result in such case?

Because if I have some prop say

item = 
{
  name:{
     details:{
          number:5
     }
  }
}

When I change number in immutable way, top level object should change too right, so why will it produce false negative?