Cover block background blurry on mobile

[rickmgithub]

Quick summary

When viewing a full width cover block background image on mobile the quality of the image drops enough to notice.

Steps to reproduce

1. AT site with StartFitter theme (although theme doesn't seem to be relevant)
2. Add cover block at the top of the home page and add a background image. The source image size doesn't seem to matter
3. Publish site
4. View the background image quality on desktop compared to mobile
5. Turning off JP images accelerator doesn't make any difference.
6. If you view via the browser inspector with the Jetpack Boost Ïmage Guide" on it shows a message about clarity -
   https://github.com/user-attachments/assets/e68130cb-6838-44d2-aec5-bca7e287ffec

What you expected to happen

The quality to remain high

What actually happened

The image is lacking clarity

Impact

Some (< 50%)

Available workarounds?

No but the platform is still usable

If the above answer is "Yes...", outline the workaround.

No response

Platform (Simple and/or Atomic)

No response

Logs or notes

8629436-zd-a8c

[github-actions]

Support References

This comment is automatically generated. Please do not edit it.

• 8629436-zen
• 8913983-zen

[vykes-mac]

@rickmgithub I tried reproducing this but I wasn't able to, maybe I'm missing something. my site is https://anda378395265.blog/

[mpkelly]

@rickmgithub, Can we add desktop and mobile pictures to this issue and maybe even the source image? I watched the video, but it's not clear to me what the issue is. Thanks.

[caitlindawn]

Reported in 8913983-zen

[jordesign]

@rickmgithub @caitlindawn - looping back to this issue - are either of you able to share screenshots of desktop and mobile to share the relative differences?

[Robertght]

I run a few tests with Twentytwentyfive and saw some differences:

Simple	Atomic	Self-hosted
This is a bit blurry(check the taillights)	It's less blurry	Same as Simple

I'm not able to see the Zoomed in behavior, but more like the crop.
I switched the theme to StartFitter and saw no differences.

@Automattic/loop would this something suitable for your team to further look into?

[davemart-in]

@Automattic/loop would this something suitable for your team to further look into?

Candidly, it doesn't feel like a great fit. We're focused on the reader and newsletters.

[Robertght]

Thank you! I focused on the "Page/Editor experience" bit and thought it was for you based on this: PdqkMK-1nV-p2

@Automattic/pixel would you be able to further look into it?