I think one of the central ways in which this play can be compared to a perspective painting is through the way in which this play almost demands us to re-examine its action and look at it from the perspective of other different characters. This is of course most prominent in the example of Shylock, who is variously maligned and mistreated by other characters and is, in one interpretation of the play, a downright villain. However, a very popular essay topic for any student studying this play asks students to reassess their perspective of this character, and encourages them to look at ways in which he might be considered more of a victim than a villain.
In the same way, it is possible to look at characters in very different ways as a result of perspective, and ways that are wildly differing. Bassanio, for example, is presented as something of a manipulative playboy at the beginning of the play, rather than the normal Shakespearian hero that we would come to expect. Jessica, too, is another character that demands us to form an impression of her. Is she a wronged daughter who is forced into leaving her father's household because of the strict way he parents her, or is she in fact a somewhat loose moral character who sells her father's riches deliberately to taunt him? Such questions abound in the play, making perspective a very important factor to be aware of in our own interpretation of what happens.