quote for X-ray website:
Since the external esp creates an external overlay, it not sure if this is detected.X-ray uses state-of-the-art methods to protect you and your online gaming experience. It will periodically take screenshots of what you are seeing in-game, and will scan for known cheats and bad processes in the background to help with cheat detection. When you are finished playing your game, X-ray will upload these screenshots to our servers, where our experienced admin team and massive userbase will help catch cheaters by reviewing screenshots and 'flagging' them if they appear suspicious.
Its not visible on for instance fraps.
The only way you can get to know this is by testing it