I also added some moss along the top, which not only looks better than seeing the black plastic pot in there, it also helps, as all mulch does, with keeping moisture in. Another advantage to this urn shape is that the bottom part is hollow, and excess water can drain well away from the bottom of the inner pot, which will make it much easier to water.
This is a trick I've used many times - if I like it, I will invest in something more expensive. But, hey, it looks pretty good as is, don't you think? Macintosh, the good little wiener dog, as usual, is not impressed.