It does handle arbitrary aspect ratios by scaling the image to fit the width of the column. What else should it do?
It also allows you to define different widths for each column. Isn’t that exactly what you want for a masonry layout?
If, for example, it rendered the child elements such that they automatically gained/lost overflow in relation to other columns, it might have some practical application that straight CSS cannot do. This would allow children to be sized vertically (effectively cropped) to produce an even square.
