For security purposes, it would probably be best to have something that hashes the key and displays it in a more human-parsable format like an identicon for verification. For a terminal, a generated phrase or sentence might be the best way to go; there are some stackoverflow posts about doing just that: https://stackoverflow.com/questions/4683551/generating-a-pse...

For the more general case of analyzing binary data, I could see something like this being useful for other tasks such as visualizing network traffic, or analyzing logs. Basically finding some way to transform the data into an optimal form for human pattern recognition.