it's a reference to the original geo cache shitter thread.
the color implies biological contents, harmless contents is a joke that people put on their grocache boxes AFTER they shit in them... the geared out hiker signifies a sc/out/ who has been roaming all day and happened to come across a geocache, in which he shits in.
it's meant to be a subtle patch, and it does a good job. you'd only get it if you were in the first few geoshitter threads, knew the color code for biological material, or understood the significance of "harmless contents" within the grocache community. look up "poop or shit in geocache" on YouTube, it will become more clear.
