Understood.
docker history --no-trunc is probably a good start.
Aside from the FROM, Which you will have to run this command on that FROM image, to determine the layers that do package installs on that image.
The history of that images dockerfile calls is in history and you can then look at the packages that are added installed etc…
Also in docker hub if you select tags tab, then an image tag latest or digest it will show a set of layers… When you select a layer it shows you what was installed…
for example
https://hub.docker.com/layers/node/library/node/latest/images/sha256-8bdcf17c651b887dbfb6de9c8604cb16790c270d920a5447eccf0368c64bc1a2?context=explore
node image layer 6…
See all the apt-get installs…
hope this helps.