Edward is hoping Sarah doesn't catch what he did- all his alternate said was that Al was alive. If there was one person in the world Edward Elric could claim he could read, it was Edward Elric. There were no reassurances about his state of being, no assurances that the fact that Al was alive would not be changing any time soon.
Which meant there's something the Gate wasn't telling them.
Edward isn't inclined to pursue that, certainly not in front of Sarah, but he worries. So, in an attempt to keep Sarah distracted from noticing what he did, he looks over at Sarah. "So now that you've gotten your question answered, how about we get mine answered? What else did you do to the grounds here, anyway? Besides the voodoo doll that has apparently amused my alternate so much?"