- art style
- a doctor might see indications of a health issue that Lisa has
- what it says about the society of that time
- geology of the landscape
- contemporary production of the color pigments
- what the picture does with you when you look at it
- and so on
Good Sci-Fi novels bring along some of these - aliens that have access to different concepts of reality, e.g. the dark forest hypothesis. The hard part is that you actually have to come up with that understanding for writing it, instead of just hand-waving it.
If you take a look at the https://en.wikipedia.org/wiki/Mona_Lisa , it can be seen from so many aspects
- art style - a doctor might see indications of a health issue that Lisa has - what it says about the society of that time - geology of the landscape - contemporary production of the color pigments - what the picture does with you when you look at it - and so on
Good Sci-Fi novels bring along some of these - aliens that have access to different concepts of reality, e.g. the dark forest hypothesis. The hard part is that you actually have to come up with that understanding for writing it, instead of just hand-waving it.