I think it's not possible to upload images directly into CRM using the import module. You can on the other hand use the Aurea CRM Interface module to mass upload documents into CRM. It's a really nice trick .
1. Create a D1 with or without D3
2. Use the Aurea CRM Interface to upload documents to CRM
Below an example request call. There should be more then enough information in the Aurea CRM documentation to make it happen. Once it works you can use it in almost all environment