Uneven gallery with a repeated loop - twig

Question

I need to make an uneven gallery, where the user can upload an infinite number of images. The gallery is composed of a pattern of 7 images that is repeated indefinitely.
The website mainly uses Paragraphs, so I created a Paragraph Gallery, where the user can directly upload the media. I set up three image styles: small, tall, and big.
I also prepared a simple CodePen with the style solution. But now I’m struggling with the Twig template. I tried some solutions from previous discussions, but they either failed or didn’t generate the images.
{% block content %}
{% for image in content.field_images['#items'] %}
{% if image %}
<div class="gallery">
<div class="gallery-left">
<div class="inner-wrapper">
<div class="inner-left">
{% if loop.first %}
<div class="field__item">
<img src="{{ image|file_uri|image_style('tall') }}" alt="{{ image.alt }}">
</div>
{% endif %}
{% if loop.index == 2 %}
<div class="field__item">
<img src="{{ image|file_uri|image_style('small') }}" alt="{{ image.alt }}">
</div>
{% endif %}
</div>
<div class="inner-right">
{% if loop.index == 3 %}
<div class="field__item">
<img src="{{ image|file_uri|image_style('tall') }}" alt="{{ image.alt }}">
</div>
{% endif %}
{% if loop.index == 4 %}
<div class="field__item">
<img src="{{ image|file_uri|image_style('small') }}" alt="{{ image.alt }}">
</div>
{% endif %}
</div>
</div>
</div>
<div class="gallery-right">
{% if loop.index == 5 %}
<div class="field__item">
<img src="{{ image|file_uri|image_style('small') }}" alt="{{ image.alt }}">
</div>
{% endif %}
{% if loop.index == 6 %}
<div class="field__item">
<img src="{{ image|file_uri|image_style('tall') }}" alt="{{ image.alt }}">
</div>
{% endif %}
</div>
<div class="bottom">
{% if loop.index % 7 == 0 or loop.last %}
<div class="field__item">
<img src="{{ image|file_uri|image_style('big') }}" alt="{{ image.alt }}">
</div>
{% endif %}
</div>
</div>
{% endif %}
{% endfor %}
{% endblock %}

Answer 1

Based on #WPhil's idea with batch I would do it like it is proposed below.
Things to note:
Image uri can be retrieved from file entity and not from media nor field reference list item this is why content.field_images['#items'].0 is not enaugh and it should be something like content.field_images['#items'].0.entity.field_media_image.entity
batch filter has three arguments and within loops like this is important to reset the index so this is why the third arggument is FALSE
Gallery paragraph file
{% import "_impression_image.html.twig" as impression %}
{% block content %}
{% for impressions_gallery_batch in content.field_images['#items']|batch(7, NULL, FALSE) %}
{# Define all image file entities for given batch of image items #}
{% set image_entities = {} %}
{% for impressions_gallery_batch_item in impressions_gallery_batch %}
{% set image_entities = image_entities|merge([
impressions_gallery_batch["#{loop.index0}"].entity.field_media_image.entity,
]) %}
{% endfor %}
<div class="impressions-gallery">
<div class="impressions-left">
<div class="inner-wrapper">
{% if image_entities.0 %}
<div class="inner-left">
{{ impression.image(image_entities.0, 'impressions_small') }}
{{ impression.image(image_entities.1, 'impressions_tall') }}
</div>
{% endif %}
{% if image_entities.2 %}
<div class="inner-right">
{{ impression.image(image_entities.2, 'impressions_small') }}
{{ impression.image(image_entities.3, 'impressions_tall') }}
</div>
{% endif %}
</div>
</div>
{% if image_entities.4 %}
<div class="impressions-right">
{{ impression.image(image_entities.4, 'impressions_tall') }}
{{ impression.image(image_entities.5, 'impressions_small') }}
</div>
{% endif %}
{% if image_entities.6 %}
<div class="impressions-bottom">
{{ impression.image(image_entities.6, 'impressions_big') }}
</div>
{% endif %}
</div>
{% endfor %}
{% endblock %}
Image item macro function (_impression_image.html.twig)
{% macro image(image_entity_item, image_style) %}
{% if image_entity_item %}
<div class="field__item">
<img src="{{ image_entity_item.uri.value|image_style(image_style) }}" alt="{{ image_entity_item.alt }}">
</div>
{% endif %}
{% endmacro %}

Answer 2

Try something along the lines of the below, I have used the batch and splice filters to break up the image array into blocks and then conditional checks to determine the appropriate image size.
{% block content %}
{% for gallery_block in content.field_images['#items']|batch(7) %}
<div class="gallery">
<div class="gallery-left">
<div class="inner-wrapper">
<div class="inner-left">
{% for image in gallery_block|slice(0,3) %}
{% if image %}
<div class="field__item">
{% set size = ( loop.index is even ) ? 'small' : 'tall' %}
<img src="{{ image|file_uri|image_style(size) }}" alt="{{ image.alt }}">
</div>
{% endif %}
{% endfor %}
</div>
</div>
</div>
<div class="gallery-right">
{% for image in gallery_block|slice(4,5) %}
{% if image %}
<div class="field__item">
{% set size = image.first ? 'small' : 'tall' %}
<img src="{{ image|file_uri|image_style(size) }}" alt="{{ image.alt }}">
</div>
{% endif %}
{% endfor %}
<div>
{% set bottom_image = gallery_block|last %}
{% if bottom_image %}
<div class="bottom">
<div class="field__item">
<img src="{{ bottom_image|file_uri|image_style('big') }}" alt="{{ bottom_image.alt }}">
</div>
</div>
{% endif %}
</div>
{% endfor %}
{% endblock %}