This is very cool for what it is, but the strict use of ASCII feels very 1990s. Even most modern terminals will render Unicode characters, and so sticking strictly with ASCII limits the usability of the tool.
As an example, on my portfolio website, I have a "photo" of myself rendered with Unicode characters [0]. I used this website [1] but lots of other options exist.
You don't need Unicode for the shaded block characters that make up your portrait, they've been in 8-bit extended ASCII since at least the introduction of the IBM PC in 1982.
Traditionally, though, the Internet ran on 7-bit ASCII only, which is what FIGlet uses.
I just used an utility like this a few days ago to generate s suitable banner for a chainloader I'm developing for my RPi3. Makes it look all professional and hacky! ASCII art, love it.
Sure, just don't use it for plain text communication with non-geeks as their web mail client won't have a monospace font set for signatures. Hence they will wonder why you end your emails with blob of crap.
https://en.wikipedia.org/wiki/FIGlet