tall vs big
Here are some unsystematic thoughts about big & tall
both are comparative/relative modifiers/adjectives
they assert (or question) a quantity about their head Noun (N)
common linguistic environments for adjectives (ADJ)
NP--> det +Q(ADJ) +N     (the tall tree)
NP be Q(ADJ)                 (the tree is tall)
NP be  Q(ADJ)-Qu           (How tall is the tree.)
comparatives are tied into the language quantifier (Q) system
this may be explicitly quantified
the tree is 10 feet tall.
whether units exist must be cultural
and ties into english intensifiers:, (e.g. very, almost....)
or it may be implicit, with the final interpretation based on the "vast database" of non-linguistic knowledge we carry around
the  tree is tall for a birch tree
the tree is twice as tall as my room.
in both examples only part of meaning is conveyed by language structure.  Listeners knowledge of birch trees and my room play an important role.
each of these spatial adjectives picks an aspect of its head and quantifies it
these aspects may be physical, e.g.aspects of shape
in some cases aspects may be  abstract
some adjectives have presuppositions about their usage
tall asserts a Q about the normally vertical dimension that greatly exceeds the other two.
Contrast "How long was your baby?" with "how tall is she?"    What;s the difference?.
big asserts something about overall volume and  shape--relative to its reference group????
While there are a number of these spatial/shape/size adjectives in English with similar meaning processes, each one in this large "lexical field" probably has its own unique characteristics.
Whorf somewhere writes that Hopi children might learn to discriminate size and shape more rapidly than English kids because of the Hopi classifier system.  Yet it is apparent that  English requires an unspeakable amount knowledge about shapes, sizes, as well.