That’s a mastiff, arguably the gentlest dog breed there is. And whoever put that tiny baby there should be arrested.
These are the kinds of episodes that lead to furious protests about “vicious dogs” and legislation that forces people to euthanize undeserving pets. Whoever posted that photo online is an irresponsible idiot as well, even if it isn’t the same dolt who put the baby there. This gives the multitude of ignoramuses who own dogs or have babies (or both) potentially deadly inspirations.