Since your workbook is not attached, no detailed advice is possible.
As for the Tableau Public viz sample, Yes, it's well arranged and designed.
I'd like to explain how well it is.
"Item hierarchy" under "Layout" tab is very useful, which provides an overview of all the visual elements.
Floating.1 with the opacity 25% creates a beautiful white veil.
Floating.2 is the text with blue veil.
Tile.1 is the contain with blue background.
Tile.2 is the image with the setting "Fit Image" and blue background.
Tile.3 is the empty text object with blue background, which I suppose is a space holder.