Images in Gmail Inbox?!

I was just about to go to bed when my nightly email from Sears, Roebuck, and Company popped into my Gmail inbox.  Normally, this is just a click & delete email.  But this one caught my attention.

Do you see that?  Just to the left of the text “Sears”? It’s the “S” from the Sears logo!  It’s also the favicon from their website.  I’ve never seen an image in the Gmail inbox before – or any inbox, for that matter.  I don’t mind it… my only question is, how can I do the same thing?

If anyone out there knows how to accomplish such a thing, let me know!