By default the icon array is built width first. Whilst this has some nice properties like using the full width available, leading to a percieved compactness, it doesn't allow easy comparison between arrays. In this case the Conservative and Labour arrays look about the same ...

A height first construction allows a better approximation of a bar chart (comparisons of length are much easier than comparisons of area so we want to emphasise those differences) and the difference between the front runners becomes more apparent.

Note the smaller values become a little tricker to compare but that the ease of countability (is that a word?) which a icon array provides can help here providing more legible information than an equivalent bar chart would at a similar scale.