Is position used instead of pivot when anchors are different from the default?

Hello, in my test scene with Canvas UI, I have one big square Image object in the center and a smaller child object inside it at its middle.

I am displaying a debug sprite at the position of the pivot of the child which I get like this:

 Vector2 GetPivotReferencePoint()
 {
     Vector2 pivot = rectTransform.pivot;
     pivot -= new Vector2(0.5f, 0.5f);
     float sizeX = rectTransform.sizeDelta.x * rectTransform.lossyScale.x;
     float sizeY = rectTransform.sizeDelta.y * rectTransform.lossyScale.y;
     pivot.x *= sizeX;
     pivot.y *= sizeY;

     return pivot;
 }

It works normally when both anchors are set to 0.5

However when I change the anchors, it seems that when I rotate the Image, it doesn't rotate around where the pivot sprite is anymore, it rotates around where localPosition is.

Does this mean the pivot isn't used when anchors are set?