home.php

<?php

// Remove default image
remove_action( 'genesis_post_content', 'genesis_do_post_image' );

/**
 * Teaser Image
 * 
 */
function be_teaser_image() {
  if( in_array( 'one-third', get_post_class() ) )
    echo '<p><a href="' . get_permalink() . '">' . get_the_post_thumbnail( null, 'be_grid' ) . '</a></p>';
}
add_action( 'genesis_before_post_title', 'be_teaser_image' );

/**
 * Feature Image
 * 
 */
function be_feature_image() {
  if( in_array( 'feature', get_post_class() ) )
    echo '<p><a href="' . get_permalink() . '">' . get_the_post_thumbnail( null, 'be_feature' ) . '</a></p>';
}
add_action( 'genesis_after_post_title', 'be_feature_image' );