Identifying/auditing docker images

[ab23]

I'm relative new to TrueNAS scale and docker but under Apps -> Manage Docker Images I see about 10 images listed, some with tags and some without. From a security conscious perspective how is one to identify legitimate images installed by either the TrueNas base system, its applications or third party apps like TrueCharts. For example if I see a Image listed with no tags shown and I cant find its sha256 checksum via an online search how would i determine what it is, whats using it, is it even running etc?