Remove container VS remove all children

1

In my experiment memory usage keeps growing a little (more, and more RAM usage after GC) when I use repeatedly:

removeChild(picContainer);
addChild(picContainer);
picContainer.addChild(pic);

istead of

while(picContainer.numChildren){
picContainer.removeChildAt(0);
}
picContainer.addChild(pic);

Is that normal?
Everything is fine when I use code with “while” loop