Another way to look at the issue is the version of .vcf which your device(s) produce.
The connection (I think) with fields and images is that a .vcf can contain a lot of fields, but I feel that it is significant that the fields correspond to a current .vcf version.
The .vcf which I first imported to /e/ was problematic, but I put it through a python script to convert it to a modern spec and it was accepted.