The visual dimension of the view area is fixed for both the cases, that is 300px by 300 px. The view point, in this example (240, 260) is also same in both the cases. However, because we have viewed the normal screen in 1.3 and zoomed it to X4 in case of 1.6, the real coordinate (img.ext) in this case show two different values.
When we zoom on the map, sever generates new map for shown. We can observe in .tmp folder. Although, img.x, img.y of step 1.3 and 1.6 is 240, 260 too, but attributes is different. Moreover, imgext changes. Summing it up, img.x, img.y of step 1.3 and 1.6 is different position on the map because zoom get new image that get new imgext. New Imgext of new image is calculated new img.x and img.y.
Because scale have an effect on define position on map. When the scale change the object on map then
change and when query old location with new scale. The object on map will show new position.