Flow in the on-line screen is the subject of much contention. It's very easy to get lost and little tags of narrative come and go, in a continual parade of 'taste and reject'. The on-line screen is iterative, interactive and disassociated. Content is separated from the static background which operates almost entirely as decoration. Bits of content are discrete.
Timing is amorphous.
Loading is the main time-determinant and that is almost random, so there can be little timing potential. It would form part of social psychology and hence of general psychology. It is not the purpose of this discussion to analyse the on-line interface to determine what concepts may be reified within it. Nor to argue about what constitutes a 'sign'. This discussion in fact has little to do with signs at all.