{% macro render_field(field) %}
  {% set model = field.object_data %}
  {% if model and model.path %}
    {{ field.form.id }}
    <img alt="" src="{{ url_for('static', filename=model.path) }}" style="max-width: 300px">
  </img>
{% else %}
  {{ field }}
{% endif %}
{% endmacro %}

{{ (field, template, render_field) }}