regression master: cover art not displayed with ytdl_hook-thumbnails

mpv Information

mpv v0.41.0-UNKNOWN Copyright © 2000-2026 mpv/MPlayer/mplayer2 projects
libplacebo version: v7.360.1
FFmpeg version: 8.1.2
FFmpeg library versions:
   libavcodec      62.28.102
   libavdevice     62.3.102
   libavfilter     11.14.102
   libavformat     62.12.102
   libavutil       60.26.102
   libswresample   6.3.102
   libswscale      9.5.102

Other Information

- Linux version:
NAME="Alpine Linux"
PRETTY_NAME="Alpine Linux v3.24"
- Kernel Version:
Linux yellow-orcess 7.1.4-0-stable #1-Alpine SMP PREEMPT_DYNAMIC 2026-07-18 16:32:59 x86_64 GNU/Linux

Reproduction Steps

mpv -v --no-config --script-opts-append=ytdl_hook-thumbnails=best https://soundcloud.com/1odumdefect/imposter-2

Expected Behavior

Expect to see a video thumbnail, as with 0.41.0.

Actual Behavior

But we see nothing, and even when forcing the window with --force-window=immediate, we have to _ to display the cover.

Log File

output.log

Sample Files

No response

I carefully read all instruction and confirm that I did the following:

• I tested and confirmed that the issue exists with the latest release version or newer.
• I provided all required information including system and mpv version.
• I produced the log file with the exact same set of files, parameters, and conditions used in "Reproduction Steps", with the addition of --log-file=output.txt.
• I produced the log file while the behaviors described in "Actual Behavior" were actively observed.
• I attached the full, untruncated log file.
• I attached the backtrace in the case of a crash.

Reproduce the issue with the provided mpv command and inspect output.log, focusing on the ytdl_hook-thumbnails=best option and the difference between normal startup and --force-window=immediate. Trace the thumbnail or cover-art handling from that entry point; done means the SoundCloud example displays its video thumbnail without requiring an additional keypress.