Tall posters? Normal posters range in aspect from 0.67 to 0.75. It's not a difficult design decision to choose a column width such that the resulting height of such posters fits on screen. For unusually tall posters, it's a matter of preference, but I'd rather the width be fixed and the height scroll anyway. Your example is an obvious play off the "A Chinese Tall Story" tagline.
There are other examples, though not many. The ones in the bottom row here are the only ones I could think of off-hand:
http://www.movieposterdb.com/movie/1442571/Gam-yee-wai.htmlbut maybe these are fan-made posters, done by maverick designers, or were intended for a special media/format other than a poster (real-life bookmarks, perhaps). They have a 0.38 aspect vs. the 0.45 of the others, so it doesn't seem to be some new standard. Since the normal aspect range is as you say, it should seldom be an issue.
As such, I think the effect is better when it has to be scrolled. It can still be opened in the viewer to see it in its entirety.
Well, it can always be interesting seeing different crops of images, but I was interested in maximizing the poster size while still being able to know at a glance that I'm seeing the poster in its entirety without having to scroll to check if there's more of it. Seeing blank space beneath the poster achieves that, as long as the blank space isn't the same color as the bottom area of the poster, so I ended up putting a border around the image control column under the poster to create a makeshift double border that only borders the bottom of the poster.
a maxheight attribute ... might be of use in some less typical situations—like where a tab is devoted for displaying posters—and the column width is not the limiting dimension. But in these situations, there is the option to limit the height of the section the images are displayed in.
I haven't been able to limit the section height using the bare-bones skin code below. Do you know of any examples where this has been done?
<section height="500">
<row>
<column>
<section height="500">
<row>
<column valign="top">
<poster autosize="true" />
</column>
</row>
</section>
</column>
</row>
</section>