Change the Default Avatar Size when using the Basic Avatar Shortcode

reset_the_default_avatar_size_on_a_page.php

<?php
/* 
 * by default the WordPress Avatar default size is 96x96
 * this code will change default WP size for page 56 (you can change this)
 * you can choose a size that is available.
 * check your Media settings in WordPress Settings Area.
*/

function my_get_avatar( $avatar, $id_or_email, $size, $default, $alt ) {
    // Check if we're on page 56
    if (is_page(56)) {
        // Define the new default size
        $new_default_size = 150; // For example, 150x150 pixels

        // Check if the size is already specified and is different from the new default size
        if ($size !== $new_default_size) {
            // Replace the size in the args array
            $args = array(
                'size' => $new_default_size,
                'default' => $default,
                'alt' => $alt
            );

            // Rebuild the avatar tag with the new size without causing recursion
            $avatar = get_avatar( $id_or_email, $new_default_size, $default, $alt, $args );
        }
    }
    
    return $avatar;
}
add_filter( 'get_avatar', 'my_get_avatar', 10, 5 );