pos/pos_default_empty_image/views/view.xml

<?xml version="1.0" encoding="UTF-8"?>
<odoo>
    <template id="assets_backend" name="pos_default_empty_image assets" inherit_id="point_of_sale.assets">
        <xpath expr="." position="inside">
            <script type="text/javascript" src="/pos_default_empty_image/static/src/js/pos_default_empty_image.js"></script>
        </xpath>
    </template>
</odoo>