Galleries
Folders and zips of pictures, in rows, and on the scenes they go with.
A gallery is a set of pictures kept in your library's folders: a folder with four or more pictures in it, or a zip of them (.zip or.cbz). x4u finds them when it looks through your folders, and Galleries shows them all by their first picture, in rows that fill the page without cropping anything. Search them by name, or sort by newest, name or how many pictures they hold. Galleries appears in the sidebar (on a phone, among the Library's tabs) once you have one.
Open a gallery to see its pictures the same way, in the order of their names (2 before 10). Click one to see it over the whole window: ← and → (or a swipe) go through them, Home and End to the first and last, and Esc, or a swipe down, closes it. The Back button closes it too, and the address says which picture is open, so a bookmark comes back to it. In a headset, they open in the Theatre: see VR in a headset, above.
Galleries and their scenes
A gallery can go with any number of scenes, and a scene can have any number of galleries, wherever each is kept. A scene's galleries show on its page, under Pictures, and a gallery's scenes under its name. A gallery that goes with just one scene is called by that scene's title.
To link them yourself, choose Link a scene on a gallery's page, or Add a gallery under Pictures on a scene's, and search for the other. The × beside a scene on a gallery's page unlinks it. Links are kept against the video's fingerprint, so they hold when you move or rename the gallery or the video.
x4u links some by itself. A gallery with a video's fingerprint in its name, in square brackets, goes with that scene wherever it's kept: Summer Shoot [a1b2c3d4e5f60718].zip, say. The fingerprint is on the scene's page, under File; click it to copy it, brackets and all. A name can hold several, for several scenes. And a gallery kept beside a video is linked to it as a first guess: one with the video's name (Scene.mp4 and Scene.zip, or a folder called Scene), or one in a folder that holds just that one video. A link you take away isn't made again.
Some pictures are missing from a gallery.
x4u shows JPEG, PNG, WebP and GIF pictures. Others (HEIC, AVIF, RAW and the like) are left out for now, as are pictures it can't read. A folder with fewer than four pictures isn't a gallery: those are usually a video's poster and the like.
I changed a gallery, and x4u still shows the old one.
x4u notices next time it looks through your folders, when it starts and every hour, and lists it again. A gallery that's moved or deleted goes from x4u; your files are never changed.