An aspect ratio of 4.5 : 1 already makes the content of the thumbnail pretty indistinct, so this could trigger for images with an aspect ratio of, say, 4 or 5 : 1 or greater in either direction.
What you want to do is show the head of the cigarette or toothpick in the 150x150 thumbnail rather than a distant view of the entire thing. IE, if the image is 800x21308, crop an 800x800 rectangle at offset (0,0) and then resize that to 150x150.
Some more examples of how it makes the content more recognizable, with the current thumbnails on the left and the proposed type on the right: http://sadpanda.us/images/853484-ZGSDW0T.png |
