Funny sign

Here's a handiwork of a trainer who was getting everyone's input and scribing before the start of a training session I recently was a part of:

I did not have the heart to correct the mistake, as there would be an element of "losing face, considering his seniority. It dawned on me that it looked like we were working in some chemistry lab or something, and it made me smile. But, trust me, that was far from it.

At least we all know what he actually meant!

It makes a really funny sign.