"Handpicked" means the file belongs to a torrent that has that file and other files.
Usually when you open Video or Audio results that come from torrents, the torrents they belong to have other files, like an info file, and a sample file so you can check the quality, or other media files that you were not interested in.
FrostWire shows you the individual files so it's easier for you to download only the files you want and none of the extra ones that could have been included in the entire torrent package.
FrostWire does the "handpicking" by file type as it presents search results.
If you want to "Handpick" manually, you can switch to the "Torrents" search results and you will see the full torrent, which you can expand with the "+" button.
A window will be shown with the contents of the torrent so you can do the "handpicking" yourself by selecting the file(s) you want and then clicking on the Download button.
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