The documentation for the plugin says:
The node row style will display each item of the view through Drupal's standard node_view()
function. Views has very little control over this output, except for the options you see. You can choose from different Build modes. By default there are "Teaser" and "Full node". You can also decide if you want to "Display links" and/or "Display node comments".
Because the output is run through the standard node template mechanism (typically node.tpl.php or a variant thereof), any decisions about what is output may be done there.
Views does add an extra 'suggestion' to the list of possible node templates: node-view-VIEWNAME.tpl.php—you may use this to theme a node specifically for the view. This can be handy for creating very small teasers and the like.
The template file could be different from node.tpl.php if there are other template files suggested for the content type, or a node in particular; the Views module itself suggests a template file whose name depends from the view name. Then, between the node.tpl.php defined from the Node module, and the same file defined from the theme, the latter is the used one.
The rendering method use for that plugin is views_plugin_row::render(), which contains the following code.
return theme($this->theme_functions(), $this->view, $this->options, $row, isset($this->field_alias) ? $this->field_alias : '');
With Drupal 7, the method is views_plugin_row_node_view::render(), which contains the following code.
if (isset($this->nodes[$row->{$this->field_alias}])) {
$node = $this->nodes[$row->{$this->field_alias}];
$node->view = $this->view;
$build = node_view($node, $this->options['view_mode']);
return drupal_render($build);
}
References
$picture
refers to the user picture, not an image field, in the node template file. Are you saying the user picture is still shown even after you remove that line?