"Short" languages typically have a programming model which makes common coding tasks implicit: ML (and other languages with type inference) make most type annotations implicit, pattern-matching languages (Erlang, Prolog, ML, Haskell, awk) make a lot of de-structuring and switching code implicit, APL dialects (APL, J, K/Q, etc.) make looping implicit, concatenative languages (i.e. Forth, Joy, Factor) and tacit / "points-free" languages (Haskell and J, again) make variables and dataflow implicit, constraint and/or logic languages (Prolog, Mercury, Oz) make search implicit, etc.

It's often a net win, but some problems inevitably clash with their model - it seems important to have some kind of escape built into the language.