You can see the familiar faces, and hear warm regards.
Just the sentence sound like a song.
first: 一张means one, but 一张张means one by one, means the writer can perceive the view full of familiar features, which all cherished by the writer.
next: everyone say hello to him, maybe not heard in the meantime, the greeting is told to the write one by one.
The sentence describe a vivid scene. You can image that a person left hometown for a long time, but when he came back he was hardly welcomed by his friends and relatives.
Hope to help!