Yeah, you can talk about how the director created a representation of King Lear if you know it.. otherwise you just have to say how "a certain represntation" was implied, depending on the techniques used.
The set text, the play itself, and (I think, anyway) the BBC type productions are the Elizabethan/Jacobean readings. They're meant to be received by people who have the mindset and thinking of elizabethans.. well, obviously the BBC film isn't but that's the idea. What were those people going through in that time, how was society run, who were the 'good' guys and who were the 'bad' guys and why?
A familial reading examines the relationships between lear + his kids and Gloucester + his sons more closely than any other aspect of the play. This can be created through set (I believe one director used the house/dining table setting to emphasise this), costumes (it can be set in any time period or place, lear may be crownless, he may be portrayed more as a father than a monarch), emphasis or deemphasis on scenes (the land-splitting scene for instance) or.. umm... the way in which Edgar defeats Edmund.
Or you could view the play in a marxist light where Lear is the monarchy or feudal system which is being overthrown by the merchant class (edmund). Edmund here can be portrayed "positively", ie he can have the favour of the audience, and simply by watching a production you can tell if this is so. How is he seen, how are his emotions displayed, how does he speak his lines? How do gloucester and edgar treat him, is he doing his evil deeds out of revenge or because he wants to rise up in the world?
umm.. other readings...
power emphasises gonerill and regan, who have been subdued by their father for so long that they relish their newfound control over him, and edmund's power over everybody else in the play.
power is LOST by lear and he only realises this once his daughters start mistreating him. distribution of power causes chaos.
feminist (related to power) looks at how the females in the play (g, r, c) harness the freedom given to them. if it's a positive reading, g + r are symbols of freedom.. their clothes, their attitude, where they appear, how fawning they are over their father in the first act, etc, explores feminist theory. or something. i don't like feminism. note that the patriarchy reasserts itself at the end of the play.
you can use characters such as the fool, kent, edgar (two faced? backstabbing?) and cordelia to back up your responses.
you can use particular scenes, read in different lights, to demonstrate your understanding of different contexts.
you should mention the audience's reaction as well as the director's vision.
and i can't think of anything more, and i'm not getting paid to write this and i'm tired.
hth.