The first thing to notice about the style in this opening scene is the use of blank verse for dialogue between the characters. Blank verse, popularised by Marlowe, is unrhymed and the meter used is iambic pentameter - the closest to the rhythm of natural English speech. This makes it particularly suitable for dialogue. At the same time, it can be used to convey a certain sense of stateliness and grandeur; therefore it is used for characters of high rank, for kings and lords, as in this play. It can be seen that, by contrast, characters of lower social standing, like the three poor men who appear briefly in this scene, speak more plainly in prose.
The blank verse is suitable as a medium for poetic and lofty imagery, generally drawn from history and mythology, particularly classical. Consider, for example, what Edward says to describe his feelings at having been separated from Gaveston, the man he loves.
Not Hylas was more mourned of Hercules
Than thou hast been of me since thy exile. (I.i.143-144)
Edward thus invokes a classical mythological precedent here, comparing himself to the great hero Hercules who loved the boy Hylas. Elizabethna drama as a whole is full of such allusions.
Much of the imagery in this opening scene also illustrates Edward's pleasure-loving, self-indulgent character. Gaveston, for instance, plans to entertain him with 'wanton poets' and 'pleasant wits' (51) and enactments of old tales and myths. In this speech, a soliloquy, Gaveston's somewhat scheming character is also revealed; he plans to 'draw the pliant king which way I please' (53).
As well as establishing the characters of Edward and Gaveston, the opening scene also shows the central conflict between Edward and various lords and clergy. They are enraged at Edward's favouring of Gaveston and his neglect of his duties as king. The main action of the play is thus set up in this introductory scene.