How to turn this text into an array with name and description?

You can do it this way:

First open the text content and save it to a variable:

$string = file_get_contents('arquivo.txt');

Next we will create an array with each line of the file.

$array = array_filter(explode("\n", $string));

Now let's map the array so that it turns the division of : into a array of 2 items. Then we will use array_combine to combine keys with the two values (keys will be "name" and "description")

$callback = function ($value) {
     return array_combine(array('nome', 'descricao'), explode(":", $value, 2));
};

$array = array_map($callback, $array);

Finally, we can see the result:

var_dump($array);

Improvements

Instead of using file_get_contents and then a explode in \n , we can evolve in this expression using the file function:

 $array = array_filter(file('arquivo.txt'));

In this case, the file function already opens the file, leaving each line in an element of array .

To scroll through the values, simply use foreach :

   foreach ($array as $key => $value) {
       echo $value['descricao'];
       echo $value['nome'];
   }

See an example at Ideone

You can use file() :

$arquivo = file('arquivo.txt');

foreach($arquivo as $index => $linha){

    list($info[$index]['imagem'], $info[$index]['descricao']) = explode(':', trim($linha));

}

This will result in:

array(2) {
  [0]=>
  array(2) {
    ["imagem"]=>
    string(12) "Art Deco.jpg"
    ["descricao"]=>
    string(20) "Descrição teste!"
  }
  [1]=>
  array(2) {
    ["imagem"]=>
    string(9) "Touro.jpg"
    ["descricao"]=>
    string(19) "Descrição teste!2"
  }
}

So you can manipulate the array as you want, it's not clear how or what the goals are after reading the data, if you want to display them you can do:

foreach($arquivo as $linha){

    list($imagem, $descricao) = explode(':', trim($linha));

    echo '<img src="'.$imagem.'" />';
    echo '<p>'.$descricao.'</p>';

}