Render an event venue when calling 'single-event.php'.

single-event.php

add_action( 'genesis_entry_header', __NAMESPACE__ . '\add_content_wrap_markup_open', 3 );
/*
 * Add content wrap around Event entry_header & render post thumbnail on single.
 *
 * @since 1.0.0
 *
 * return void
 */
function add_content_wrap_markup_open() {
	$event_id = (int) get_the_ID();

	printf( '<div %s>', genesis_attr( 'before-entry-header-wrap' ) );

	echo add_venue_image_to_single_event();
}


/*
 * Add an event venue image to the single-event template.
 *
 * @since 1.0.0
 *
 * @return void
 */
function add_venue_image_to_single_event()    {
	if ( is_post_type_archive( 'events' ) ) {
		return '';
	}

	return render_event_venue_image( $event_id );
}

@rgadon107 You split it out into a separate function, i.e. add_venue_image_to_single_event() , when you need to reuse it in other places. If no and it's a singular usage for just this, then do this:

function add_content_wrap_markup_open() {
	$event_id = (int) get_the_ID();

	printf( '<div %s>', genesis_attr( 'before-entry-header-wrap' ) );

	if ( ! is_post_type_archive( 'events' ) ) {
             render_event_venue_image( $event_id );
        }
}

You don't need to echo because the function render_event_venue_image( $event_id ); is doing (or should do) the rendering. Why? Because it says its expected behavior is to render the event venue image.

@hellofromtonya: Given that I only plan to get the image for the single-events template, then it makes sense to use the conditional in the function add_content_wrap_markup_open() and call the function render_event_venue_image( $event_id ).

Your point about about reusing the 'get_image' function for other use cases in a project is a good one. In that situation, it would make sense then to build the 'get_image()' function in a more generic way to use as a helper function or method throughout the project.