Here are closeups of the stuff Julisa got along with the infamous letter, clipped from the photo taken by (and kindly provided to Irene by) Sarah Taylor of the Bee-Picayune.
This all explains the two logos on the letter. Apparently the perpetrator could not come up with a high resolution NSF logo for the trophies, and resorted to clip art that says "SCIENCE" on it. (The objects designated on the pedestal are obviously a telescope, a microscope, and, um, a corn dog.) So for consistency, the clip art logo appeared on the letterhead.
Update: It didn't take long for somebody to find the original. (h/t JM) Here's a similar item available in single quantity. Here's what appears to be the logo itself:
Update 6/19: Links to Beeville stories by myself and others here