Mt. Aventine

Today, we were treated to a tour of Mt. Aventine, a Tidewater Plantation on the Potomac River. My photo is a view through a window in one of the upstairs rooms.  In the middle right of the frame, you can see a pair of bald eagles. There are several eagle nests in the park. 
When I loaded the photo in LR and adjusted it, I noticed a weird anomaly. 
I pointed it out to my husband. He tried to make sense of it as a trick of lighting but failed. I have no clue what it was or is. The red is baffling. Check out the bottom left window frame.