The first image failure that I see this on the dashboard was 10/09/20 at r268294, and has to do with LFC integration enabling overflow hidden which could have introduced the constant image failures. The change was introduced here https://trac.webkit.org/changeset/268294/webkit.
I can reproduce this on r268294, but unable to reproduce on r268293.
run-webkit-tests --ios-simulator imported/blink/fast/css/zoomed-intrinsic-width.html
Regressions: Unexpected image-only failures (1)
imported/blink/fast/css/zoomed-intrinsic-width.html [ ImageOnlyFailure ]
I have marked this test as image failure while this issue is investigated.
Created attachment 411143 [details]
*** Bug 217608 has been marked as a duplicate of this bug. ***
Created attachment 411186 [details]
ChangeLog entry in LayoutTests/ChangeLog contains OOPS!.
Created attachment 411188 [details]
Committed r268382: <https://trac.webkit.org/changeset/268382>
All reviewed patches have been landed. Closing bug and clearing flags on attachment 411188 [details].