Why does the test fail?

test.lisp

(in-package :cl-user)
(ql:quickload :fiveam)

(defun top-left (board)
  (car board))

(defun (setf top-left) (value board)
  (setf (car board) value))

(fiveam:test top-left-accessor ()
      (let ((board '(:1 :2 :3 :4 :5 :6 :7 :8 :9))
            (expected-board '(:empty :2 :3 :4 :5 :6 :7 :8 :9)))
        (setf (top-left board) :empty)
        (fiveam:is (equal board expected-board))))

(fiveam:run! 'top-left-accessor)

;; Result of running this
;; Failure Details:
;;  --------------------------------
;;  TOP-LEFT-ACCESSOR []:
;;       EXPECTED-BOARD evaluated to (:EMPTY :|2| :|3| :|4| :|5| :|6| :|7| :|8| :|9|), which is not EQUAL to (:EMPTY
;;                                                                                                      :|2|
;;                                                                                                      :|3|
;;                                                                                                      :|4|
;;                                                                                                      :|5|
;;                                                                                                      :|6|
;;                                                                                                      :|7|
;;                                                                                                      :|8|
;;                                                                                                      :|9|)..
;;  --------------------------------