// Here is the fix
function diff_bp_activity_entry_meta() {

    if ( bp_get_activity_object_name() == 'blogs' && bp_get_activity_type() == 'new_blog_post' ) {?>
        <?php
        global $wpdb, $post, $bp;
        $theimg = wp_get_attachment_image_src( get_post_thumbnail_id( bp_get_activity_secondary_item_id() ) );
        ?>
        <img src="<?php echo $theimg[0]; ?>" >
        <a class="view-screenshot activity" href="<?php bp_activity_thread_permalink(); ?>">View Screenshot</a>

    <?php }
 
    if ( bp_get_activity_object_name() == 'blogs' && bp_get_activity_type() == 'new_blog_comment' ) {?>
        <a class="view-comment activity" href="<?php bp_activity_thread_permalink() ?>">View Comment</a>
    <?php }
 
}
add_action('bp_activity_excerpt_append_text', 'diff_bp_activity_entry_meta');