Good question! Unfortunately, images are not support in the iCal import process. iCal feeds themselves do not include file attachments that can be used to import from one source to another. You would need to add images after import in order for imported events to have images.
Sorry for the confusion! Does this help answer your question? Please let me know.
I’m afraid there is currently no way to sync both content and images between two sites. The Facebook Events add-on can import all content–including images–from Facebook to WordPress but that’s not quite the same thing. I think the closest you could do is use the WordPress export tool (Tools > Export) from the first site, then import the file it produces using the WordPress Importer.
Sorry again for the bad news, but does this at least help?