Somalis and Ethiopians are a mix of people like the Dinka in South Sudan with Natufian population that no longer exist because the Middle East has changed a lot genetically since then but they would had been closest to a modern day Yemeni.

Ethiopians and Somalis also have something else called "Mota". Closest living population to them is the Hadza. Hunter gatherers in Tanzania. Ethiopians have slightly more of that than Somalis.

There is also a lot of variation within Ethiopian ethnic groups.

But to sum it up they both have a lot of West Eurasian ancestry. They are not 100% Subsaharan African like 23andme labels them as. This is why they look different than other Subsaharan Africans