Yes, there's a temporary sort of shimmery glow over whatever you've spotted but it's very easy to miss when you're either moving or happen to be looking in the other direction. Might it be an improvement if the Alt tooltip key always highlighted anything that had been discovered along with whatever else it already pops up? Maybe even with some marker on the tooltip text to indicate that the highlighted item had been discovered by a perception check? Or even if we got a little message in the combat log or elsewhere on screen that said what the perception check had discovered? Even if that doesn't tell us exactly where it is, we'd at least know what we're looking for!
But yes, I think in the Ogre's building it could well be the support beam as I think there's a perception check on that. And I think in Nettie's room it's highlighting something you'd need to use to make an antidote to her poison stick should you need or want it, perhaps her cauldron?
