Hi,
Base rock has no life, it is dried out and it's only use is to help build up the rock, it will eventually become live rock when you have enough critters to set up house and move in. The rock you got is not base rock...because it was rock sold for a nano tank, it looks like broken portions of branch rocks. I used branch rock in my seahorse tank so I recognize it. The branch rock doesn't look like the regular LR, it has fewer nooks and crannies but it does have the same good critters. I do see some some light touches of coraline here and there on it too, so don't be disappointed.
I always hand picked my rock and looked for some nice purple on it to help build up the coraline. I never understood purchasing rock on-line if you have a fish store within 50 miles, it's heavy and it has to be cycled because of die off during shipping anyway. I'm sure in a few weeks you will start seeing life emerge on the rock, just like the rock we buy at the LFS.
By the way
...I like how you stacked it, it looks good...
I hope it is very stable and you didn't build it on top of the shifting sand...rock must be on the bottom and the sand added afterward...if you did build it on the sand, remove the rock and push the sand to one side...rebuild your rock and push the sand back around it. It's hard to tell in pictures if the rock is on or under the sand, so I figured I would say something just in case. I wouldn't want you to have a rock slide that could crush your critters or break your tank.