This one /azu/ regulars probably know, and Azuma knows for sure as he's Japanese.
I'd say with many bricks kids would build complex structures.
But Yotsuba's habit of building brick towers (it was more than in one chapter, pic taken from chapter 60) reminds following element of buddhism.
Sai no Kawara (Riverbed of the Netherworld, Japanese Limbo for Children)
"The legend of Sai no Kawara is attributed to the Jōdo Pure Land Sect from around the 14th or 15th century AD. According to the legend, children who die prematurely are sent to the underworld as punishment for causing great sorrow to their parents. They are sent to Sai no Kawara, the riverbed of souls in purgatory, where they pray for salvation by building small stone towers, piling pebble upon pebble, in the hopes of climbing out of limbo into paradise. But hell demons, answering to the command of the old hag Shozuka no Baba (also called Datsueba, or Jigoku no Baba), soon arrive and scatter their stones and beat them with iron clubs."
(quote and all info from http://www.onmarkproductions.com/html/sai-no-kawara.html )
In my opinion, concept of Ten Judges of Hell has flaw, which is in question "Who will judge the judges?".
It must be such a pleasure to sit in Hell eternally! Yes? No? There's saying which means something like prisoner and his warder are almost in the same situation.