[BUG] On mobile app, thumbnail should scale to fill, not stretch

[wedlj2094]

Description of the Bug

On latest TestFlight v0.0.0 build 98 version of app, when the aspect ratio of a book does not match the user preference, the image becomes stretched to fill the space.

Expected Behavior

The thumbnail image should scale to fill the available space, not stretch.
Just like web app behaves.

Steps To Reproduce

No response

Where is this issue happening?

• Web App
• Mobile App
• Server

Server & Client Details

Server Details:

• Release Channel: experimental
• Server OS: macOS 26.3
• Using Docker: No
• Server Version: 0b339ac

Client Details:

• Device: iPad Air 4th gen, iPhone Air
• OS: iOS 26.2
• Browser: Not Applicable

Additional context

No response

[Arklaum]

The reason behind that is because many of my books that are technically in the 1 : √2 ratio (about 1 : 1.414) actually are encompassed in a range of slightly different ratios varying from like 1 : 1.405 to 1 : 1.425. If they're not stretched, then there are always small bits cut off which is annoying (I was still thinking about changing web but didn't get around to anything yet).

But as a further improvement I was thinking of either:

1. Having the real image ratio show (with a max aspect ratio of 1.6 and minimum 1.4) though that would of course necessitate things looking slightly uneven.
2. Or having the thumbnail size be fixed, and if the image's ratio is too different from the selected ratio, then use grey empty space to fill the difference (similar to Apple Music). This is the option I am leaning towards.

Is it the difference in behaviour between mobile and web that you dislike, or the stretching is what you dislike?

[wedlj2094]

I personally really dislike stretching.
If the thumbnail is scaled to fill, yes some content becomes invisible but the remaining visible parts are intact,
but if we stretch to fill, the whole thumbnail becomes a mess with inaccurate proportions.

I think the only sane options are

1. scale to fill (current web app behavior)
2. use grey empty space (or even thumb hash colors since we have them)

preferably user having a choice between them.

[aaronleopold]

Is it the difference in behaviour between mobile and web that you dislike, or the stretching is what you dislike?

I'm going to guess the latter, but just to speak to my own opinion I think we can have another preference added to switch between some kind of fill/cover or what you had mentioned:

if the image's ratio is too different from the selected ratio, then use grey empty space to fill the difference

That feels like it would cover all the bases for how people might want their thumbs to fit without introducing uneven layouts

Edit: Ha, hit send at the same time I guess. I think it sounds like we are on the same page