Remote upload refers to an upload that was started on another computer or web browsing session. So for example, if you start an upload via our desktop app and then log in on your web browser, the web browser will show Remote Upload for the desktop app upload.
If you're using a web browser, the Remote Upload message can also appear if you restart your web browser without first canceling an in-progress upload. Digital Pigeon is unaware that you have abandoned your upload so it assumes it's uploading from another Remote computer. In this case, you will need to add the files again and restart the upload (alternatively check out our desktop app which can handle computer restarts).