Why is row="[object Object]" column="[object Object]" in all of the elements?

[boatcoder]

https://codesandbox.io/s/sorting-in-window-table-forked-wmzhl?file=/src/index.js

<td class="table-cell" row="[object Object]" column="[object Object]" index="0" style="width: 50px; flex-grow: 50; display: inline-block; overflow: auto; box-sizing: border-box;">
  <div row="[object Object]" column="[object Object]" index="0">
    Demetris
  </div>
</td>