XAML网格问题：贪吃蛇游戏实现与教程效果不符求助

我正在学习C#，跟着YouTube上一则使用XAML和C#开发贪吃蛇游戏的教程实操（进度至46分钟）。完成网格设置并运行代码后，发现界面效果和教程不一致：

教程界面效果：

我的界面效果：

我确认没有遗漏任何步骤，现将当前的XAML和C#代码附上，恳请熟悉XAML和C#的开发者帮忙排查差异：

XAML代码 #

<Window x:Class="SnakeGame2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:SnakeGame2"
        mc:Ignorable="d"
        Title="Snake" Height="500" Width="800"
        Background="{StaticResource BackgroundColor}"
        Foreground="{StaticResource TextColor}"
        FontFamily="{StaticResource MainFont}"
        WindowStartupLocation="CenterScreen"
        Icon="Assets/icon.ico">


    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <TextBlock x:Name="Scoretext"
                   HorizontalAlignment="Center"
                   VerticalAlignment="Center"
                   Text="Score: 0"
                   FontSize="22"
                   Margin="10"/>
        <Border x:Name="GridBorder"
                Grid.Row="1"
                BorderBrush="{StaticResource GridLinecolor}"
                BorderThickness="1.5"
                HorizontalAlignment="Center"
                VerticalAlignment="Center"
                RenderOptions.EdgeMode="Aliased">
            <UniformGrid x:Name="GameGrid"
                         Width="400"
                         Height="400"
                         Background="{StaticResource GridBackgroundColor }"
                         SnapsToDevicePixels="True"
                         RenderOptions.BitmapScalingMode="HighQuality">
            </UniformGrid>
        </Border>
    </Grid>
</Window>

C#代码 #

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace SnakeGame2
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        private readonly int rows = 10, cols = 15;
        private readonly Image[,] gridImages;
        public MainWindow()
        {
            InitializeComponent();
            gridImages = SetupGrid();
        }

        private Image[,] SetupGrid()
        {
            Image[,] images = new Image[rows, cols];
            GameGrid.Rows = rows;
            GameGrid.Columns = cols;    
            
            for (int r=0; r < rows; r++) 
            { 
                for(int c=0; c < cols; c++)
                {
                    Image image = new Image
                    {
                        Source = Images.Empty
                    };
                    images[r, c] = image;
                    GameGrid.Children.Add(image);
                }
            }
            return images;
        }
    }
}

感谢您的宝贵时间！

内容的提问来源于stack exchange，提问作者André Vieira