Given that concreteness is a term often used in communication or language subject which deals with the issue of being distinct, explicit, and expressive instead of being vague and broad. To be more concrete in communication, numbers and facts are often used, thereby making the recipient or receiver of the message or communication fully understand the point of communication without thinking or guessing what the message could actually mean.
Hence, in this case, the statement "In Concreteness, nothing is left to Imagination" means to express oneself to the extent that the recipient fully understands the message without second-guessing the true meaning of the message. Messages like "Elevate your political status in just 20 days." "Drugs made for pregnancy, " "The battery that lasts for 10 hours, " etc.
