wagtail_bakerydemo/bakerydemo/jinja2/base/include/header.html

<div class="container">
    <div class="row">
        <div class="col-md-7 base-header">
            {% if page.image %}
                <div class="image">
                    {% set photo=image(page.image, "width-500") %}
                    <img src="{{ photo.url }}" width="{{ photo.width }}" height="{{ photo.height }}" alt="{{ photo.alt }}" />
                </div>
            {% endif %}

            <h1>{{ page.title }}</h1>
        </div>
    </div>
</div>