レジストリへpushしてpullするとかなりサイズが違うのね。

$ docker images --tree WARNING: This is an experimental feature. The output may change and shouldn't be depended on. i Info → U In Use IMAGE ID DISK USAGE CONTENT SIZE EXTRA swift_discord_bot-observant:latest dfc46048c8e6 7.47GB 1.69GB └─ linux/arm64 dc9e215b19d8 7.47GB 1.69GB ghcr.io/norio-nomura/swift_discord_bot… 481df181764c 5.46GB 1.28GB ├─ linux/arm64 b41bae123576 5.46GB 1.28GB └─ linux/amd64 c611daa6e57b 0B 0B