Huge difference

SELECT * FROM gallery2 WHERE topic_id="885739" UNION SELECT * FROM gallery2 WHERE topic_id="67389" UNION SELECT * FROM gallery2 WHERE topic_id="1650332" UNION SELECT * FROM gallery2 WHERE topic_id="1604616" UNION SELECT * FROM gallery2 WHERE topic_id="1659580" UNION SELECT * FROM gallery2 WHERE topic_id="1449795" UNION SELECT * FROM gallery2 WHERE topic_id="1525309" UNION SELECT * FROM gallery2 WHERE topic_id="1339388" UNION SELECT * FROM gallery2 WHERE topic_id="1136140" UNION SELECT * FROM gallery2 WHERE topic_id="622221" UNION SELECT * FROM gallery2 WHERE topic_id="1166485" UNION SELECT * FROM gallery2 WHERE topic_id="985362" UNION SELECT * FROM gallery2 WHERE topic_id="673161" UNION SELECT * FROM gallery2 WHERE topic_id="1663054" UNION SELECT * FROM gallery2 WHERE topic_id="1667818" UNION SELECT * FROM gallery2 WHERE topic_id="1065706"