As a member of an advanced civilization that can build rockets of intra-solar travel, I am currently training my dog to sit, lie down, and touch my palm with her nose.
It may only speak to their evaluation of our capabilities.
Ah, but can your dog stack rocks? ;~)
This is similar to the argument (I’m looking at you NDT) that aliens wont try to communicate with us because they consider us as we consider ants. This is flawed. We are sentient and clearly capable of many types of communication - ants are not. My proof, look around you.
All any alien would have to do is observe us and it would be obvious that we were more than capable of much more than stacking stones. Ancient Egyptians had the same capabilities as we do. I have trouble believing that aliens would have misunderstood us that much.
You would think that you Advanced Guys had better things to do with your time, like clearing up those darn black holes.
Ronnie James Dio wrote a song about this very idea.
The wrong thing about that isn’t that ants don’t communicate - they clearly do. The wrong thing about that is the idea that humans just ignore ants and don’t try to figure out what they’re saying to each other. Entomologists spend a lot of time researching ant communication. Probably, alien scientists would do the same with us, even if we’re shockingly primitive because we communicate primarily by making noises with our food-intake chute.
You don’t even have to go back that far. There were these two stonemasons I hired to repair the brickwork on my previous old house before I sold it, because they seemed to be doing a good job on the stone facade of a new house going up across the street. They did a magnificent job repairing the brickwork.
This was around fifteen years ago. I’m convinced nobody could do that kind of work today. In fact, I suspect they might have been aliens – they had advanced technology that could cut through brick like a hot knife through butter! It was clearly not of this world! 
Bee, crow, dolphin, and whale communication have not been obvious to us and it’s taking us quite a while to ascertain that they do, in fact (or not in fact), have some method of communicating complex ideas.
To ascertain that, we generally start at the simplest level and work up.
But they do not alter their environment the way humans do. The very fact that they were building structures to an afterlife would have clued the aliens to the fact that we are capable of much more. We were already stacking stones, stacking them higher is not a leap in engineering.
“What the **** is a N * U * B * I * A * N?”
A Sudanese TV sitcom about ancient war medics?
What is “What Trelane called Uhura?”
Bees don’t alter their environment? Lots of animals build complex structures: bees, termites, beavers, bowerbirds, prairie dogs, etc. For most of history, that hasn’t caused humans to think that we should try to communicate with them.
For most of history we weren’t capable of leaving Earth. Also, most of our scientific knowledge is less than 250 years old. ISTM that any civilization capable of interstellar travel would probably have the same amount of curiosity that has lead us to the amount of knowledge we have now
Hey, Gilda tried.
I’m Zimbabwean, albeit a pale version. Those aliens must have gone on something of an insane building spree, because aside from Great Zimbabwe, there are hundreds of smaller structures, built in the same way, scattered around Mashonaland. There was one about 10km from my house, so I could ride my bicycle there. The concept that aliens (and/or the alternative wack-job theory that it was Portuguese traders) build Great Zimbabwe ignores those off-shoots. Why would aliens build a small fortress on top of a hill in a rural backwater from stone harvested on site (the stone was fractured using fire and water alternatively) when they had the facility to travel presumably interstellar distances, and therefore had slightly better technology than “build it with rocks”?
The Mashona built the thing. They built the outlying forts. They abandoned them when their empire collapsed. It really is that simple.
I enjoyed reading von Däniken when I was about 13, even though - at that tender age - I had serious doubts.
Note that this is all surmise. There is no historical record of these off-world guest-workers. And the Egyptians kept pretty good records. Clearly they were undocumented aliens, and the Pharaoh was just getting it done on the cheap.
There’s many, many orders of magnitude difference between a beaver dam and New Your City. An alien probably would not be able to tell the difference between a log jam and a beaver dam.
However the 1500’ tall Central Park Tower, encased in flat glass surfaces and lots of 90 degree angles would certainly catch a visitors attention. It reeks of higher intelligent design in a way that beehives and termite mounds do not.
And the reason it only showed up now was they had to send it to Altair to be developed.
That is ridiculous. Everyone knows the lab is at Wolf 359. It is less than half as far away, and, honestly, why would you have a film lab around a blue giant? Wolf 359 is dim enough, they can do the printing part without even having to use a safelight.
I might be mistaken, but I’m pretty sure both are mute because that pic oozes Polaroid emulsion.