I understand, thanks, I check the Africa example very carefully, let us take this example to discuss.
I believe, What make most people confused, is that re-pins on an image before and after grouping that image, this is what I care.
what about if grouping an image itself and set pins to this group, then set pins to the image within that group again?
what is THE OBJECT OF REFERENCE of the edge to that image in this situation?
Before I tried on Africa example again, I guess there might be three possibilities:
1# it is still the edge of scene or document, if yes, why allow person set pins again to that image just after setting pins to that group?
2# at that time, THE OBJECT OF REFERENCE of that image will be the border lines of that group. if this one is right, I can understand and I think it is reasonable. but there is no explanation in tutorials.
3# No matter grouping an image or not, once grouping it and set pins, the edge of THE OBJECT OF REFERENCE to that image is always the edge of scene or document.
so if grouping a image itself, the image showed up at frontend page, will be exactly limited within the group borders area with the proportions of that image? if I am wrong, please correct me.