I went and looked and apparently this wasn't well-documented in the Wiki (sorry about that), but top/left coordinates are based on the center of an object in Roll20. So that's why when you set the left value to the same thing they are center-aligned. If you want to align them based on their top-left corner, you would need to take into account the width of the object. For example: obj2.set("left", Math.floor(obj1.get("left") - obj1.get("width") / 2 + obj2.get("width") / 2)); Would align obj2 to the same place as obj1's left-hand side. (Untested, but that should be right, anyway)
