Insert a users avatar into the members column in leaderboards instead of adding a new column.

mycred-bp-leaderboard-member-column-example1

/**
 * Insert Avatar in Leaderboard Column
 * @since 1.0
 * @version 1.0
 */
function mycred_pro_bp_leaderboard_avatar_column( $content, $row, $group_id, $point_type ) {

	return get_avatar( $row->user_id, 64 ) . $content;

}
add_filter( 'mycred_bp_leaderboard_member_column', 'mycred_pro_bp_leaderboard_avatar_column', 10, 4 );