He's perhaps asking about a technique of adding texture that looks like tree bark (uncannily like the real thing) to the surface of a Pelican case, most likely this:
http://www.easy3dcamo.com/
I believe they're talking about using construction adhesive that comes in caulk gun cartridges to be used for the final 3D skin on the trailcam box, and about using a silicon rubber mold to make it. Last I'd checked, the molds were no longer offered by the website above but it might give the OP inspiration to make his own.
Yes, it's mostly for people that you need to hide a trail cam but that's not insignificant. Trail cams get stolen all the time, unfortunately it's the flash that'll give them away regardless of camo unless you use IR-only filtered flash with IR film/ digicam sensor. Dope growers and poachers don't like to leave evidence behind. (They're also likely wearing night vision goggles that will see the flash, nowadays.)