a place for zinesters - writers and readers
Back before photoshop and digital image editing was so standard, it was common for a coffeeshop to have a piece of plastic that was a halftone filter that you would literally place over an image to turn it into dots.
now the machine simulates it itself with the effect that is often just called "photo". if you turn it to the photo setting, it's actually halftoning your image.
then blow it up drastically (rotating its position on the glass 90 degrees each time) and you should get that effect.
but here's the most important thing: imitation is flattering but it's just imitation.
your use of this knowledge is best served to take it somewhere new, rather than copy (har har) what someone else has been doing for 25 years.