I assuming these symbols are used due to a low literacy rate. Is that correct?
I should have added that the other factor making symbols more important here than elsewhere is the multiplicity of languages.
You are correct. In fact, one of the ways Musharraf rigged the elections in 2002 to enable the mullah parties to win was to simultaneously ban secular parties and allowing “non-party affiliated” mullahs to contest elections under the symbol of a Book. The Book symbol resembled the Quran and allowed the Mullahs to campaign saying that a vote against the book is a vote against the Quran. Musharraf used these types of manipulations to make sure that the Mullahs win enough seats for him to tell the US - “It’s me or the Mullahs - who do you choose”
Thank God for the Bush administration for preventing Musharraf from using dirty tricks and thereby let us see how popular the mullahs really are.