No problem!
You’re almost there. But notice that you try to use a variable $pod_image without first declaring it and setting its value.
<?php if ( $last_row['pod_image'] ) { ?>
<?php $pod_image = $last_row['pod_image']; ?>
<img src="<?php echo $pod_image['sizes']['medium']; ?>" alt="<?php echo $pod_image['alt']; ?>" />
<?php } ?>
