While using shapes to remember Hiragana can be a good way to memorise the characters, the problem I see with your method is that the shapes/images bear no relation to the sound of the character. For example I might remember 'chair' to write the character か but 'chair' doesn't help me link か to the sound /ka/. The biggest problem learners have with Kana is relating the sounds to the characters.
There are already several methods for memorising Hiragana and Katakana using shapes available online that do use images that no only help you remember the shape, but also the sound, as in the example posted by FinancialWar.
I think it would be more useful to learners to use shapes/images that also help them associate the character with its pronunciation.