It's a bit of a statement for what you're trying to communicate with that lid - professional experience, political statements, personal "this is neat"...
And part of this is a for me the lid of the laptop is something that I'd need to be able to be comfortable with displaying in front of a CxO without worry about if they may be offended or not (though perl might be offensive to some).
So far no one has ever been offended by this though. HN is far more sensitive than the average CTO.
That can be a healthy attitude outside of work. People love personality.
But at work, that's not a healthy attitude. You're there to work together, not to be uncompromising in expressing yourself. Your stickers are probably fine, but I can also imagine plenty of musical artists that would certainly be offensive (and rightly so) to some people, whether for their lyrics or for their criminal behavior -- and then the attitude of "that's more your problem than mine" is not gonna fly.