A gap between two things is narrow if the two things are quite close together and there is not a lot of room between them. The street in the picture is very narrow. The opposite of narrow is wide.
Something is short if the highest part of it is much lower than the top of similar things. The woman in the picture is much shorter than the man in the picture. The opposite of short is tall.
Something is tall if the top of it is much higher up than the top of similar things. The person wearing the scarf on the left of the picture is taller than the other person in the picture. Giraffes and basketball players are tall.
The opposite of tall is short.