How to activate the ASUS watermark of camera on ZenFone3 Zoom (ZE553KL) ?
1. Launch Camera app > Click the gear icon on upper-left corner for Settings menu > Click to activate ASUS watermark
2. After you click and enable the ASUS watermark, Taken with Zenfone 12X Zoom would be shown at the bottom left corner of the photo you took (see below sample image).