Seen in a basement bazaar was this sign. The unfortunate grammar opens up many possibilities.
Are the owners urging people not to stick to the pillars (the guy in the orange sweater certainly seems tempted). Alternately, is it an exhortation to the pillars themselves, urging them not to stick the walls, thereby triggering the collapse of the whole basement?
Walls is clearly capitalized. Walls is probably a regular who hates when people stick to him as he enjoys his personal space and not being sticky (and I can respect both). Thus, be kind and do not stick on Walls.
No doubt Spiderman popped in here last week and in his effort to avoid the crowds was climbing all the walls. These folks probably found that a bit unsettling and didn’t enjoy cleaning up the excessive web residue thereafter