<div class="container">
<div class="row">
<div class="col-lg-12">
<h1 class="page-header">Images</h1>
</div>
<hr>
{% if images %}
{% for key,value in image.items() %}
<h4>{{key}}<h4>
<hr>
{% for image_name in value %}
// have a condition here to check if its first image, then
display it with a <div> tag.
if(first) {
<div class="col-lg-3 col-md-4 col-xs-6 thumb">
<img class="img-responsive" src=" {{url_for('send_image',
filename=image_name)}}">
}
//end here
<div class="col-lg-3 col-md-4 col-xs-6 thumb">
<img class="img-responsive" src=" {{url_for('send_image',
filename=image_name)}}">
<hr> </div>
{% endfor %}{% endfor %}{% endif %}
</div>
</div>
вот как бы я это сделал.Надеюсь, это поможет.