Though the best are often small in size + quite minimal, in my experience I would say logos are actually one of the most difficult graphics to produce. There are many bad logos + only a few great ones in this world + what differentiates them is nuanced. The thought process of creating one is like writing a poem, the expression of feelings + ideas is given intensity by particular attention to imagery + narrative. Some clients feel just because a logo is 100px * 100px (Scalable Vector Graphic) that it hasn’t taken thousands of hours + many ideas based on indirect concepts to produce the best possible result. The beauty of a small image or a font that tells us what a brand is about is regularly the consequence of genius.