We have to fit all given images provided by plugins into the 1024x1024 texture window which we have reserved for plugins. That's a difficult problem so we just throw images into the window in a really simple way. With a recent update we replaced the algorithm by a better one. However, a perfect solution might still not be found. In computer science this problem is related to the Knapsack Problem. The problem is NP-complete which means that it's expensive to find a perfect solution (or at least no efficient algorithm could be found yet).