It is (arguably) more helpful because you now have this extra information:

1. The computed string (the "got") actually looks like a digest of the right length and the right alphabet. This tells you that the code producing that string is performing the right action, just on the wrong source data. Before, the string could have been "" or "aaaaa" or "I can haz cheeseburger" for all you knew.
2. The computed and expected strings are entirely different, not just say one character out so you have not introduced a typo in the expected string.

You now have more confidence that the underlying problem is indeed that the source data for the digest is not what it should be, rather than some issue elsewhere in your code or your test script.