Why is an extra array of arrays being created inside an array of JSON objects in javascript

Question

Why is an extra array of arrays being created inside an array of JSON objects in javascript

I am adding JSON objects to an array using the push command. After adding this array, only two JSON objects are displayed. Then I add the whole array to another array containing 7 other arrays. Finally, when I access the array of JSON objects, it shows two JSON objects and one additional array containing the same objects and array. Here I have attached the code and result of the result. How can I solve this?

prevArrhythBeats.push(
  {
      x: annotationPacket[k].timestamp,
      title: annotationPacket[k].annotBeat.a_type,
      text: annotationPacket[k].annotBeat.a_desc
  }
);

dataFactory.setPrevData(prevChOne, prevChTwo, prevGrid, prevLeadChange, prevMotion, prevArrhythBeats)

dataFactory.setPrevData = function (cOne, cTwo, grid, lead, mot, beat) {
                prevData.push(cOne);
                prevData.push(cTwo);
                prevData.push(grid);
                prevData.push(lead);
                prevData.push(mot);
                prevData.push(beat);
}