I don’t believe this phrase applies to presentations. Apparently, the phrase originates in the American advertising industry in the early 1900’s. Sorry it’s not from a Chinese or Japanese philosopher.
In modern presentations images can serve three functions: amplification, clarification and decoration. You want your pictures to perform one or more of those functions, especially amplification and clarification. What every presenter is shooting for is to have a picture communicate one, or a few important words. Words like success, urgency, hope, concern, safety and enthusiasm to name a very few.
One picture can convey an emotion that the average speaker may never convey – never mind how many words they tried to use. Pictures can be very powerful, select them wisely. Select them to convey one powerful word, not a thousand.