what it it called when you type letter after letter and make a picture?

Answer 1

ascii art.

ascii stands for 'american standard code for information interchange' and is referring to standard text, comprising of 96 characters just like you're reading - they are:
!"#$%&'()*+,-./0123456789:;<=>?
@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_
`abcdefghijklmnopqrstuvwxyz{|}~

art just refers to the creation of patterns from ascii.

ascii art is a very old thing, which was perhaps born out of the inability of basic printers to print pictures and so pictures were created out of text characters instead.

it was used alot in the early nineties on bulletin boards for graphics again because real graphics were not practical for use on slow dial-up connections of 28k/56k, it is still used by the 'scene' groups who release pirated hollywood films in their extended ascii '.nfo' files which accompany the video files:
http://www.vcdquality.com/index.php?page=nfo&id=65441

it has seen a rebirth in recent years by users of instant messaging programs like yahoo and msn messenger.

Answer 2

ASCII Art

Answer 3

ASCII Art