Complex sentence: However he found the figure of Christ to be "traditional", while the "absence of spatial elaboration overall is felt to be all the more vexing", while overall the image, he believed, lacked depth of field and compositional balance.
Split into simpler sentences: However he found the figure of Christ to be "traditional", and wrote that the "absence of spatial elaboration overall is felt to be all the more vexing". Overall the image, he believed, lacked depth of field and compositional balance.