I'm going to speculate that the carving was done due to a bulge in the concrete due to the shoddy materials used for the forms.
I don't think I have ever seen that amount of porosity and outright voids in a vertical pour since a visit to Yemen in 2011 to inspect a construction project we were making the steel structure for. It was painfully clear that the Ministry of planning and development had been bought off as every phase had been rubber stamped without and accompanying inspection documentations.
I suspect on this house construction there will be a huge amount of spackle patching before the moisture barrier is sprayed on