Maybe this is easier to read:

```diff
  $blobList = $this->blobProxy->listBlobs($this->containerName);
+ return array_map(function($blob) { return $blob->getName(); }, $blobList->getBlobs());
-  $blobs = $blobList->getBlobs();
- $blobs = $blobList->getBlobs();
- $keys = array();
-
- foreach ($blobs as $blob) {
-     $keys[] = $blob->getName();
- }
-
- return $keys;
```