The specific number of spaces in the indentation is unimportant as long as parallel elements have the same left justification and the hierarchically nested elements are indented further.
2.
The main difference in formatting is : the brown color, the ordering of the rows, the left justification of the row headers, squeezing the row headers.
3.
In the " Forced left justification " subsection of Wikipedia : Images # Using _ images, nothing is mentioned, and nothing is mentioned at Wikipedia : Images # Image _ choice _ and _ placement either.