Not "drawable" but there's this "mipmap" folder.

Android Studio has changed a lot since this tutorial was made. As Ozhan correctly pointed out, you should take the icon images out of the drawable folders, and place them in the respective mipmap folders, replacing the default icons in the process. If you're replacing them in Android Studio, then when you copy an image across to the mipmap folder, you will be asked which of the mipmap folders you'd like it to go in, as Android Studio has visually condensed all the mipmap locations (mipmap-hdpi, mipmap-mdpi, etc.) into one mipmap folder for easy of use.

What you should do with the rest of the images in the drawable folders is: 1) Open the res folder in finder/explorer 2) Delete the drawable folder 3) In its place, paste in all of the drawable folders from the download (drawable-hdpi, drawable-mdpi, etc.)

Now, when you go into Android Studio, you'll still see just the drawable directory, but as with the mipmap folders, this is Android Studio condensing them down visually. Now when you load the app on different size devices, the correct size image will be loaded.

The mipmap folder is meant to be where you put your launcher icon and the drawable folder is for everything else. You don't strictly have to use it that way if you don't want to.