(Note: I hope someone will let me know if the Greek comes out wrong, and if so what browser and operating system were in use. On my screen, it looks fine except that acute accents not combined with breathings are pointed straight up, or even slightly back, as if they were graves – grave accents, I mean, not tombs.)
I begin with Tueller’s text in Volume I of the new Loeb Greek Anthology, which is the same as Gow and Page’s except for the punctuation:(1)
Οὐκ ἔσθ᾽ οὗτος ἔρως, εἴ τις καλὸν εἶδος ἔχουσαν
βούλετ᾽ ἔχειν, φρονίμοις ὄμμασι πειθόμενος·
ἀλλ᾽ ὅστις, κακόμορφον ἰδών, πεφορημένος οἴστρῳ,
στέργει, μαινομένης ἐκ φρενὸς αἰθόμενος,
οὗτος ἔρως, πῦρ τοῦτο. τὰ γὰρ καλὰ πάντας ὁμοίως 5
τέρπει τοὺς κρίνειν εἶδος ἐπισταμένους.
3 οἴστρῳ Pl : ἰοῖς Π
The first paragraph of Gow and Page’s commentary summarizes the epigram:
“Reason plays a part in desire for a beautiful girl; unmixed passion is experienced only by the lover of a plain girl.”
The next paragraph offers a brief evaluation of the poem:
“The theme is original, the style is remarkably plain; there is hardly a word which is not at home in the most ordinary prose . . . and there is no attempt at clever phrasing.”
Although Gow and Page do not connect the statements of the two paragraphs quoted, it seems to me that we should do just that, and that Argentarius illustrates his recommendation of plain girls by writing it in an uncharacteristically plain style. So much is fairly obvious. In a further twist, it is not at all clear whether the poet is in love with a plain girl himself. The plain, prosaic, entirely undithyrambic style of the epigram suggests not only the plainness of its subject(s) but the sanity and levelheadedness of the speaker. If he is totally sober and sensible, he presumably prefers beautiful girls after all. It seems that Argentarius, in his usual evasively witty way, leaves us guessing as to whether he loves plain girls himself, and thus whether he is to be counted among the wise or the unwise.
(1) The Greek Anthology, Books 1-5, translated by W. R. Paton, revised by Michael A. Tueller, Harvard, 2014; The Greek Anthology: The Garland of Philip, edited by A. S. F. Gow and D. L. Page, 2 vols., Cambridge, 1968. Page was primarily responsible for Argentarius (I, vii). It is conceivable that the puzzling variant ἰοῖς (3) originated as a misguided gloss ᾿Ιοῦς on οἴστρῳ: certainly the myth of Io combines a gadfly and love, in a way that few others do.
The Greek has some issues in Chrome (Windows 7). Here’s a screenshot: http://imgur.com/VgCiqzJ.
The Greek looks exactly the way you describe it here (OS X 10.10.5, Safari).