It directly uploads to the ipad - you insert the SD card into the adapter, the adapter into the slot, and the photo app opens up with the whole batch and asks if you want to upload them. You can hit yes and upload them all or cherry pick and just upload some of them. I don't believe it checks for dupes though, so if you don't reformat your card after uploading, it'll run through all of them again the next time you try to upload.
The portable drive is totally independent of the ipad. It has its own slot for an SD card (and other slots for other media formats) and when you stick a card in, it automatically copies all of the data to a directory on the drive. That thing has a lot more capacity than the ipad so its a really good safety measure and then I can cull from the ipad knowing I'll still have the original files if I really need to go back and get something. When I spent a month away from home last April and was shooting pretty heavily nearly every day, I filled up the 64gb ipad and had to cull a LOT of shots from it, but I still had 'em on the portable drive if I'd ever needed them. I also uploaded the better shots of each day to Flickr as an absolute last ditch backup, so that if I lost everything in travel somehow, at least I'd have those snapseed processed files to have SOMETHING... Fortunately, nothing went wrong and I'd have been just fine with only the ipad, but I don't know that I'd trust JUST the ipad or any other single data storage option...
-Ray
