The image type, file size and min/max dimensions are fine for GNOME Software; the aspect ratio is a big change.
Is the intention that the whole banner image be always visible? Banners are currently stretched to fit the screen width and cropped to fit the available space.
If we just updated the banners to the new aspect ratio then without any futher changes it would look like this:
If we fit them vertically it looks like this:
Note the text and icon would not be used - just showing these examples to give an idea of the GNOME Software behaviour. I used the currently promoted snap (krita) which has a much wider banner and cropped it to be 1:3.
If we accept the banner aspect ratio of 1:3 I see us as having the following options:
- Centering the banner as shown in the last two screenshots.
- We need to work out what to put in the space either side of the banner (if anything).
- Not a lot of work, and should be upstreamable.
- Showing multiple banners to fill the available space.
- Resolves the whitespace issue from above.
- Reasonable amount of work, but doesn’t align with existing banners used upstream so may not be acceptable.
- Use a new home screen layout in GNOME Software.
- Allows us to place banners in any desired layout.
- A lot of work and expected to be sufficiently Ubuntu specific that would not be upstreamable.
If we go with options 2 or 3 then we’d probably also need to do option 1 for non-Ubuntu users of GNOME Software to have an acceptable experience.