Metallic elemental mercury (what you see in the picture) is relatively harmless to touch. Arguably, it’s more dangerous to rub a lead ingot, for example. However, mercury vapours (and mercury does evaporate slowly but consistently) absorb quite easily when you breath them with a ton of undesirable effects, often related to central nervous system, which is never a nice thing. Broken mercury thermometer won’t kill you. Playing with the puddle inside a non-ventilated room might kill you in several decades. Working in the non-open-air environment where mercury is always present will slowly worsen your health as mercury accumulates.

Organic compounds of mercury are what actually is nasty. A short contact with a few millilitres of that — and you will have to recover for a long-long time, if ever. However, the scary stories about methylmercury rarely mention that there are other organic compounds that are just as toxic or worse. I wouldn’t get close to any organic cadmium compound, for example, and would be extremely wary of its inorganic salts too. The thing is it’s extremely unlikely that you encounter any of these chemicals ever in your life, and if you do encounter them, then you are likely a professional who knows exactly how and why you are to deal with them.