Ah - OK. Get it.
Amsterdam, as one of I think only two or three cities, is divided up into "stadsdelen" (literally: cityparts). Each "citypart" has, incredibly, its own elected council, and - I had to look this up - its own aldermen ("wethouders"), but no mayor.
Zeeburg is one of Amsterdam's "cityparts". So it's part of the city, the people there also vote for Amsterdam's overall city council, it's just that it's one of some dozen administrative subdivisions.
Fatima Elatik was never an alder(wo)man of Amsterdam city, I was mistaken - she used to be an Amsterdam city councillor; and now she is one of four aldermen of Zeeburg. Go
here, click "bestuursinformatie", then "Dagelijks Bestuur" to see a picture (yes, she wears a headscarf). I guess the programme you heard decided to make that into "deputy mayor" and Zeeburg into a "town in Amsterdam", but no matter.