I know exactly which one you are referring to, but I no longer have a physical Revelation book. Also, for some reason, the online copies do not include the illustrations....I wonder why that is.
The illustration that is burned in my mind shows a woman looking up towards the sky and having utter panic at what she was seeing and I thought also possibly another person behind her had a gun trying to shoot at whatever was coming at them from the sky. I remember staring at that wondering how they knew what exactly the tribulation would be like.