<?php
// symulacja pobranych rekordów z bazy danych
// $rows = $conn->query($conn, "SELECT img FROM Upload ORDER BY id DESC");
$rows = [
[ 'img' => 'ccccc.jpg' ],
[ 'img' => 'bbbbb.jpg' ],
[ 'img' => 'aaaaa.png' ]
];
foreach ($rows as $row) {
echo '<img src="img/' . $row['img'] . '" alt="' . $row['img'] . '" />';
}