The created custom block is
It’s just a custom block with an image on the left and a textbox on the right, allowing you to change the image on the left and the textbox on the right.
In addition, the smartphone display is arranged vertically.
This is a slightly unusual form of the layout element “media and text”.
Arbitrary section
You may provide arbitrary sections, in the same format as the ones above. This may be of use for extremely complicated plugins where more information needs to be conveyed that doesn’t fit into the categories of “description” or “installation.” Arbitrary sections will be shown below the built-in sections outlined above.