A gallery brings its own layout, images per row, and image order with it — those live in the app. The theme block adds the settings that depend on where the gallery sits in your design: spacing, captions, the lightbox, and the shape of Grid tiles. That split lets the same gallery feel different on different pages without touching the gallery itself.
Where the Settings Live
Block settings are in the Shopify theme editor, not the app:
Open Online Store > Themes > Customize.
Navigate to the page where you added the Image Gallery block (Home, a Product page, a custom page, etc.).
Click the Image Gallery block in the sections list on the left.
Settings panel opens on the right — every change previews live.
There is no Layout setting here. Layout, images per row on desktop and mobile, image order, and Mosaic tile sizes are all set on the gallery’s page in the app, so the block can never disagree with the preview you approved there.
Settings Reference
Gallery ID - The unique ID of the gallery you want to show (for example,
gal_abc123). Copy it from the Install to Theme screen, or from the Installation page in the app. Switching the ID swaps which gallery this block displays without touching anything else.Grid tile shape - Square (1:1), Portrait (3:4), Landscape (4:3), or Original ratio. Only applies when the gallery’s layout is Grid.
Images per row - Leave on App setting (recommended) so the block uses the desktop and mobile counts you set on the gallery. Picking a number here overrides the gallery for this block only, and that fixed number then applies on phones too — so use it only when one specific page needs a specific count.
Gap (px) - The space between images, from 0 to 32 pixels. Lower for a tight magazine feel, higher for an airy look.
Carousel height - Adapt to image (recommended) keeps each image’s own proportions so nothing is cropped; the strip is as tall as the tallest slide. Fixed height crops or letterboxes every slide to one height instead. Only applies to the Carousel layout.
Carousel height (px) - The height used when you choose Fixed height, from 200 to 800 pixels.
Image fit - Also only for Fixed height. Choose Fill (crop to fit) so images fill the whole height (some cropping), or Fit (original ratio) so the whole image is visible with empty space around it.
Enable lightbox on click - On by default. When on, visitors can click any image to open a full-screen lightbox.
Lightbox background - Dark or Light. Only shows when the lightbox is enabled.
Image titles - Choose Hidden, Show on hover, or Show below image to control how each image’s title appears.
Image descriptions - The same three options for the image’s description. Titles and descriptions are written per image in the app, and each can be shown, hidden, or placed independently.
Tips for Different Use Cases
Homepage hero - Carousel, with the gallery set to 1 image per row and Carousel height left on Adapt to image.
Product gallery - Grid, Square tile shape, small gap.
Editorial lookbook - Masonry with titles shown below each image.
Featured collection - Collage with a gap of 4-8 px, so the hero tiles read as one composition.
Block settings only affect the block you’re editing, so adding the same gallery to another page lets you try different spacing or captions there without losing this one.