Got Approve and Welcome Message in the same Day

In the same day, I got two emails from USCIS.

The First one is the Approve Notice:
"On July 22, 2006, after approving your application, we ordered you a
new card. Your card will be mailed to you as soon as it is ready...."

The second one is the Welcome Notice:

"On July 24, 2006, a welcome notice was mailed for this case. If 30
days have passed and you have not received this notice. Please call the
National Customer Service Center at [phone] during business
hours....."

What is the Welcome Notice?

My Case Infor:
EB1, NSC
140/485 PD Sep, 2003
140 REF Jan, 2004; Approved : April 2004
Changed Job at May 2005 by EAD cards
485 REF June 2006, Approved notice and Welcome Notice: Today.

Good Luck all,( if you want my lawyer information, I can share with you)