In centralized countries, not only population, media and economic power are concentrated, but people give more attention to central locations. While this is not inherently bad, this behavior extends to micro-blogging platforms: central locations get more attention in terms of information flow. In this paper we study the effects of an information filtering algorithm that decentralizes content in such platforms. Particularly, we found that users from non-central locations were not able to identify the geographical diversity on timelines generated by the algorithm, which were diverse by construction. To make users see the inherent diversity, we define a design rationale to approach this problem, focused on the treemap visualization technique. Then, we deployed an "in the wild" implementation of our proposed system. On one hand, we found that there are effects of centralization in exploratory user behavior. On the other hand, we found that the treemap was able to make users see the inherent geographical diversity of timelines. We measured these effects based on how users engaged with content filtered by the algorithm. With these results in mind, we propose practical actions for micro-blogging platforms to account for the differences and biased behavior induced by centralization.