I feel a little dumb asking something like this, but I just downloaded the Kirby3.5 starter kit. Everything’s ok but - trying the new gallery block, the images are displayed just like plain unordered list. What I am doing wrong?
Nothing.
In line with Kirby’s philosophy not to make any assumptions about how you want to render your frontend, the basic HTML output for the gallery is just a list inside a figure tag.
You can either style this markup, or what you would do in most cases, is overwrite the gallery.php block snippet with your custom HTML and class attributes (which would be completely different depending on whether you favor your own custom styles, Tailwind, Bootstrap or any other framework, whether you want to make this a slider or a lightbox with their custom JS and required markup…
So the default is just basic semantic markup with no styling.