And speaking of Apollinaire...

Incidentally, Apollinaire's pictorial poems rarely consisted of just the "concrete" (shaped) part, though from the way they're described and quoted, you'd think the shaped part of the poem was the whole thing. For instance, the concrete poem below that begins "Tant d'explosifs sur le point..." is actually itself only the opening of  a longer poem called "Du coton dans les oreilles" (something like "cotton in your ears"). Much of the poem is fairly conventional in form, if still difficult. He continues to explore the possibilities that print offers to verse by, say, using larger font to signify "words" of the bugle call, or by surrounding the words "Les cenobites tranquilles" with a sort of frame, as though what the dugout is called informally among the soldiers were a physical label. 

On the whole, the concrete poems are much easier to understand in context, so it's a bit annoying that on Wikipedia (of course) and such those parts are presented on their own, as though each were the entirety of the poem in which it's found.

It's also annoying that if he's known in English at all it's as "the concrete poems guy" when he also wrote many very traditionally-formed poems (though again, they are difficult). In fact, I get the impression (though I haven't counted)  that these are actually the majority in Calligrammes. 

 Here's a lovely example of one of these more traditional ones. The assonance and gentleness of the rhyme are features almost un-reproduceable in English; only Frost and Wilbur really come close.

Un oiseau chante

    Un oiseau chante ne sais où
    C'est je crois ton âme qui veille
    Parmi tous les soldats d'un sou
    Et l'oiseau charme mon oreille


    Écoute il chante tendrement
    Je ne sais pas sur quelle branche
    Et partout il va me charmant
    Nuit et jour semaine et dimanche


    Mais que dire de cet oiseau
    Que dire des métamorphoses
    De l'âme en chant dans l'arbrisseau
    Du cœur en ciel du ciel en roses


    L'oiseau des soldats c'est l'amour
    Et mon amour c'est une fille
    La rose est moins parfaite et pour
    Moi seul l'oiseau bleu s'égosille


    Oiseau bleu comme le cœur bleu
    De mon amour au cœur céleste
    Ton chant si doux répète-le
    À la mitrailleuse funeste


    Qui chaque à l'horizon et puis
    Sont-ce les astres que l'on sème
    Ainsi vont les jours et les nuits
    Amour bleu comme est le cœur même