Once you send a link to Downie, it starts processing it. Depending on the link, your connection bandwidth and other aspects, this can several seconds.
Once the link is processed, Downie will add a download to the list:
By default, Downie will start the download and will choose the best quality available for you. You can turn off the automatic download start and modify the quality settings in Preferences > General.
Right-clicking the row, or clicking on the preview icon will produce a menu with various per-download options. These options vary depending on the link and on the state of the download. Major features of the menu include:
Cancelling
You can cancel the link processing using the cancel button. Note that the link that is currently being processed will not be cancelled and will need to finish processing.