C# How is ctrl+A input turned into a smiley?

While learning about Console.ReadLine() in depth, I found something very peculiar.

I wrote following code in Main method in a console application in C#

string str = Console.ReadLine();
Console.WriteLine(str);
Console.WriteLine(str.Trim());
Console.ReadLine();

When I ran the code, I gave input as ctrl+A and pressed enter. I see smileys (not able to post image, as I don't have permission to do it yet).

I want to understand, how is it showing the smiley? Shouldn't it show ^A or empty/blank (empty because when I tried debugging it, it showed string value a " ".)