Can someone explain what is the main container for the image element in the provided code snippet? I couldn't find any clear explanation on the tutorial website, so insight on how this specific section of code operates would be greatly appreciated.
var imgData = publisher.getImgData();
var img = document.createElement("img");
img.setAttribute("src", "data:image/png;base64," + imgData);
// Need to identify the parent DIV for the img here
document.getElementById("containerId").appendChild(img);