Ribbit messages containing an image not working correctly

#import "InboxViewController.h"
#import "ImageViewController.h"
#import "MSCellAccessory.h"

@interface InboxViewController ()

@end

@implementation InboxViewController


- (void)viewDidLoad
{
    [super viewDidLoad];

    self.moviePlayer = [[MPMoviePlayerController alloc] init];

    PFUser *currentUser = [PFUser currentUser];
    if (currentUser){
        NSLog(@"Current user: %@", currentUser.username);
    }
    else {
        [self performSegueWithIdentifier:@"showLogin" sender:self];
    }

    self.refreshControl = [[UIRefreshControl alloc] init];
    [self.refreshControl addTarget:self action:@selector(retrieveMessages) forControlEvents:UIControlEventValueChanged];
}

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];

    [self.navigationController.navigationBar setHidden:NO];

    [self retrieveMessages];
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    // Return the number of sections.
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    // Return the number of rows in the section.
    return [self.messages count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];

    PFObject *message = [self.messages objectAtIndex:indexPath.row];
    cell.textLabel.text = [message objectForKey:@"senderName"];

    UIColor *disclosureColor = [UIColor colorWithRed:0.553 green:0.439 blue:0.718 alpha:1.0];
    cell.accessoryView = [MSCellAccessory accessoryWithType:FLAT_DISCLOSURE_INDICATOR color:disclosureColor];

    NSString *fileType = [message objectForKey:@"fileType"];
    if ([fileType isEqualToString:@"Image"]) {
        cell.imageView.image = [UIImage imageNamed:@"icon_image"];
    }
    else {
        cell.imageView.image = [UIImage imageNamed:@"icon_video"];
    }

    return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    self.selectedMessage = [self.messages objectAtIndex:indexPath.row];
    NSString *fileType = [self.selectedMessage objectForKey:@"fileType"];
    if ([fileType isEqualToString:@"Image"]) {
        [self performSegueWithIdentifier:@"showImage" sender:self];
    }
    else {
        PFFile *videoFile = [self.selectedMessage objectForKey:@"file"];
        NSURL *fileUrl = [NSURL URLWithString:videoFile.url];
        self.moviePlayer.contentURL = fileUrl;
        [self.moviePlayer prepareToPlay];

        [self.view addSubview:self.moviePlayer.view];
        [self.moviePlayer setFullscreen:YES animated:YES];
    }

    NSMutableArray *recipientIds = [NSMutableArray arrayWithArray:[self.selectedMessage objectForKey:@"recipientIds"]];
    NSLog(@"Recipients: %@", recipientIds);

    if ([recipientIds count] == 1) {
        [self.selectedMessage deleteInBackground];
    }
    else {
        [recipientIds removeObject:[[PFUser currentUser] objectId]];
        [self.selectedMessage setObject:recipientIds forKey:@"recipientIds"];
        [self.selectedMessage saveInBackground];
    }
}


- (IBAction)logout:(id)sender {
    [PFUser logOut];
    [self performSegueWithIdentifier:@"showLogin" sender:self];
}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if ([segue.identifier isEqualToString:@"showLogin"]) {
        [segue.destinationViewController setHidesBottomBarWhenPushed:YES];
    }
    else if ([segue.identifier isEqualToString:@"showImage"]) {
        [segue.destinationViewController setHidesBottomBarWhenPushed:YES];
        ImageViewController *imageViewController = (ImageViewController *)segue.destinationViewController;
        imageViewController.message = self.selectedMessage;
    }
}

#pragma mark - Helper methods

- (void)retrieveMessages {
    PFQuery *query = [PFQuery queryWithClassName:@"Messages"];
    [query whereKey:@"recipientIds" equalTo:[[PFUser currentUser] objectId]];
    [query orderByDescending:@"createdAt"];
    [query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
        if (error) {
            NSLog(@"Error: %@ %@", error, [error userInfo]);
        }
        else {
            //We found messages!
            self.messages = objects;
            [self.tableView reloadData];
            NSLog(@"Retrieved %d messages", [self.messages count]);
        }

        if ([self.refreshControl isRefreshing]) {
            [self.refreshControl endRefreshing];
        }
    }];
}


@end

[recipientIds removeObject:[[PFUser currentUser] objectId]];
        [self.selectedMessage setObject:recipientIds forKey:@"recipientIds"];
        [self.selectedMessage saveInBackground];
    }

}

- (UIImage *)thumbnailFromVideoAtURL:(NSURL *)url
{
    AVAsset *asset = [AVAsset assetWithURL:url];

    //  Get thumbnail at the very start of the video
    CMTime thumbnailTime = [asset duration];
    thumbnailTime.value = 0;

    //  Get image from the video at the given time
    AVAssetImageGenerator *imageGenerator = [[AVAssetImageGenerator alloc] initWithAsset:asset];
    imageGenerator.appliesPreferredTrackTransform = YES;

    CGImageRef imageRef = [imageGenerator copyCGImageAtTime:thumbnailTime actualTime:NULL error:NULL];
    UIImage *thumbnail = [UIImage imageWithCGImage:imageRef];
    CGImageRelease(imageRef);

    return thumbnail;
}