And that new creature borne without her dew,/ Full of the makers guile with usage sly/ [Archimago] taught to imitate that Lady trew [Una],/ Whose semblance she did carrie under feigned hew. (I.i.46).
In our first example of weird fake people in this poem, Archimago's construction of a false version of Una relies heavily on the study and imitation of her appearance and manners.
Then when [Arthur, Timias, Una, and Redcrosse] had deployld [Duessa] tire and call,/ Such as she was, their eies might her behold,/ That her misshaped parts did them appall,/ A loathly, wrinckled hag, ill favoured, old,/ Whose secret filth good manners biddeth not be told. (I.viii.46)
Although Duessa spends most of Book I posing as a beautiful woman, when she's finally captures by Arthur and others he reveals that her appearances is actually very ugly… a manifestation of her inner, moral ugliness.
…[Guyon] rusht into the thick,/ And soone arrived, where that sad pourtraict/ Of death and dolour lay, halfe dead, halfe quick. (II.i.39)
When Guyon finds Amavia dying with her baby playing in her own blood, the horror of the scene is described in terms of art: their image is called a "sad portrait."
Faire Sir (said [Guyon]) if in that picture dead/ Such life ye read, and vertue in vaine shew,/ What mote ye weene, if the trew liuely-head/ Of that most glorious visage ye did vew? (II.ix.3)
After Arthur comments on the beauty of the image of Gloriana on Guyon's shield, Guyon reminds him that a picture pales in comparison to the appearance of the queen herself.
The great Magician Merlin had deuiz'd,/ By his deepe science, and hell-dreaded might,/ A looking glasse, right wondrously aguiz'd/ Whose vertues through the wyde world soone were solemniz'd. (III.ii.18)
The famous magic mirror in which Britomart see her future love, Arthegall, combines the act of looking at oneself—the typical use for a mirror—and looking at one's future. Nifty.
For round about, the wals yclothed were/ With goodly arras of great maiesty,/ Wouen with gold and silke so close and nere,/ That the rich metall lurked priuily,/ As faining to be hid from enuious eye. (III.xi.28)
Even before we learn that the tapestries in Busirane's house depict scenes of rape, we know something is wrong because they "lurk" and "fain"—not exactly normal for visual artwork.
The warlike Mayde beholding earnestly/ The goodly ordinance of this rich place,/ Did greatly wonder, ne could satisfie/ Her greedy eyes with gazing a long space… (III.xi.53)
As Britomart checks out the house of Busirane, she gets a little bit too obsessed with looking at it and seems unable to feel that she can fully take all of it in.
At last the most redoubted Britonesse,/ Her louely Amoret did open shew;/ Whose face discouered, plainely did express/ The heauenly pourtraict of bright Angels hew… Till Blandamour, who thought he had the trew/ And very Florimell, did her display:/ The sight of whom once seene did all the rest dismay. (IV.v.13)
The tournament of Satyrane features a competition between ladies for the title of Most Beautiful. You'll notice the difference between Amoret's beauty being associated with heaven and angels while the False Florimell's beauty is associated with "dismay."
Of things vnseene how canst thou deeme aright,/ Then answered the righteous Artegall,/ Sith thou misdeem'st so much of things in sight? (V.ii.39)
Correcting the socialist leanings of the Giant with Scales, Arthegall appeals to a divine natural order that means we can't always know why things are the way they are.
So stood [Calidore] still long gazing thereupon,/ Ne any will had thence to moue away,/ Although his quest were farre afore him gon;/ But after he had fed, yet did he stay,/ And sate there still, vntill the flying day/ Was farre forth spent… (VI.ix.12)
Forgetting his quest, and transfixed by the beauty of Pastorella, Calidore's obsessive looking reminds us of Britomart's thousand-yard stare in the house of Busirane.