How do I get a list of the content of a page to loop through? I have a document type with an image picker and I want to check the width of my image with a Saving or Publishing event (doesn't really matters at this point)

private void ContentServiceSaved(IContentService sender, SaveEventArgs<IContent> e)
    {
        foreach (var node in e.SavedEntities)
        {
            if (node.ContentType.Alias == "productDetail")
            {
                //Need foreach to loop through node's content
                //This forloop is the one I used in a media saving event, but I need to do this
                //with the image picker of my document before it gets published or maybe saved
                //----------------
                foreach (var mediaItem in e.SavedEntities)
                {
                    //if it's an image, the content type will tell you.
                    if (mediaItem.ContentType.Alias == "Image")
                    {
                        var width = Convert.ToDouble(mediaItem.Properties["umbracoWidth"].Value);
                        var height = Convert.ToDouble(mediaItem.Properties["umbracoHeight"].Value);

                        if (height / width != 1)
                        {
                            //Sending a message will cancel the process, so you don't
                            //need an else (unless you want to do something else with the image of course.
                            string msg = "Ratio is not 1:1. Please make sure the width and height of your image is the same.";
                            e.DisposeIfDisposable();
                            e.CancelOperation(new EventMessage("Wrong Ratio", msg, EventMessageType.Error));
                            e.Messages.Add(new EventMessage("Wrong Ratio", msg, EventMessageType.Error));
                            return;
                        }
                    }
                }
                //----------------
            }
        }
    }