Hiding div based on user role

Basically, just check inside the action if an array of the current user’s roles contains the wholesale role.

function content_below_checkout_button() {
    if ( in_array( 'wholesale', wp_get_current_user()->roles ) ) {
        echo '<div style="text-align: center"><img style="margin-top:20px; display:inline-block;" src="/uploads/2020/07/image.png'.$photo->name.'"/></div>';
    }
}

add_action( 'woocommerce_review_order_after_submit', 'content_below_checkout_button' );

I’m not sure what’s going on with the rest of your code, but I assume it was working.