Correct, it may not work on mobile because the font size is 6pt and the line may be too wide for a phone. That's something I should fix. The exposure, however, probably just needs a slider to increase or decrease what is considered black.
I assume from that screenshot that there isn't color support, but if you're on Linux, you can do something similar locally with color support:
$ mpv -vo caca /dev/video0
At least on my Debian Trixie system, it looks like they aren't building mpv with aalib support anymore, an older monochrome image-to-text library, just libcaca, but I know that in the past mpv and mplayer have supported that as well.
This will, among other things, permit viewing video on a plain text console.