Open images in photoshop panel

I use references a lot when I'm drawing, and I'm trying to build an extension that will let me open images in a separate Photoshop panel to make things easier. But I've been driving myself nuts because I can't get images to appear in the panel at all. I eventually want to be able to drag and drop images as well copy and paste content in the panel, but right now, I'm just trying to open an image with a typical file input.

Here's the html:

<div id="content">

        <div class="ref">

            <div class="startmssg">

                <i class="fas fa-arrow-down fa-3x"></i>

                <p>Drag & drop reference images here</p>

            </div>

          <!--Element where I want to place the image-->

          <img class="refpic">

        </div>

    </div>

    <nav>

        <label class="topcoat-icon-button--large--quiet" title="Add new reference image file">

                <i class="fas fa-image fa-2x"></i>

               <!--The file input for the image-->

                <input type="file" id="openref" accept="image/*" multiple>

            </label>

        <button type="button" id="delref" class="topcoat-icon-button--large--quiet" title="Delete reference image">

                <i class="fas fa-trash-alt fa-2x"></i>

            </button>

        <button type="button" id="infobttn" class="topcoat-icon-button--large--quiet" title="Info">

                <i class="fas fa-info-circle fa-2x"></i>

            </button>

    </nav>

The jsx function:

function readImage(input) {
    if (input.files && input.files[0]) {
        var reader = new FileReader();
        reader.onload = function (e) {
            $('.refpic').attr('src', e.target.result);
        }
        $('.startmssg').hide();
        reader.readAsDataURL(input.files[0]);
    }
}

And the main.js file:

 $("#openref").change(function () {
            csInterface.evalScript('readImage(this)');
        });

The code above works in jsfiddle, but not in the panel. I can't figure out what I'm doing wrong.