关于帧动画的一个小问题？

storyboard 里有三个按钮 tag 分别为 0 1 2 （剪刀石头布）
 一个imageView 
 这句
 [_playerImageView setImage:_imageData[1]];
 对动画有啥影响？？？
 代码如下：
 //
 // SKViewController.m
 // 剪刀石头布
 //
 // Created by apple on 13-9-13.
 // Copyright (c) 2013年 www.skyming.com. All rights reserved.
 //

#import "SKViewController.h"

@interface SKViewController ()

@property (strong, nonatomic) NSArray *imageData;

@end

@implementation SKViewController

(void)loadDataAndAnimation
 {
 _imageData =@[[UIImage imageNamed:@"剪刀"],
 [UIImage imageNamed:@"石头"],
 [UIImage imageNamed:@"布"]];

[_playerImageView setAnimationImages:self.imageData];
 [_playerImageView setAnimationDuration:5.0];
 [_playerImageView startAnimating];


}

(void)viewDidLoad
 {
 [super viewDidLoad];
 [self loadDataAndAnimation];
 }


(IBAction)playGame:(UIButton *)sender
 {
 NSLog(@"%d",sender.tag);
 if ([_playerImageView isAnimating])
 {
 NSLog(@"stop");
 [_playerImageView stopAnimating];
 [_playerImageView setImage:_imageData[sender.tag]];
 }else
 {
 NSLog(@"start");
 [_playerImageView startAnimating];
 // 以剪刀停 石头开始 石头停 --- 为什么是 剪刀 ？ 
 // 
 [_playerImageView setImage:_imageData[sender.tag]];

}


}
 @end