The nails in the image appear dirty and rough, often associated with someone who works with their hands in dirty or manual labor environments. So, a common answer to the riddle-like question “What do you call a person who has nails like that?” is:
A mechanic, gardener, construction worker, or someone who does hard physical work.
In other words, nails like that usually belong to someone who works hard with their hands rather than neglecting hygiene.
If this is a riddle expecting a witty or humorous answer, it might be:
“A hardworking person” or simply “Someone who works with their hands.”
No insult intended — just the natural result of hands-on work!