Are these two phlox the same plant?
Zipped around the web and found the following from the Kemper Center for Home Gardening:
" 'Laura' is a garden phlox cultivar which typically grows in an upright clump to 3-4' tall. Fragrant, tubular flowers (1/2" to 1 inch diameter) with long corolla tubes and five flat petal-like lobes are purple with white eyes. Individual flowers are densely arranged in large, terminal, pyramidal clusters (panicles to 6-12" long) atop stiff, upright stems which seldom need staking. Long mid to late summer bloom sometimes extends into early fall. Narrow, opposite, pointed, lance-shaped leaves (to 5" long). Good fresh cut flower. The name phlox is derived from the Greek word for flame."
Other places, like Bluestone, list "Little Laura" as a cultivar that will grow 18"- 24". Must be cousins, Idabean.
Now you've made me think about planting more phlox. They do brighten up August. Thinking back, how did you make with your fountain design?