Step 1, describing, gives us the deeper and further critique.
emotion
outline
foundation
perspective

The artist above used rapid brushstrokes 

Emotional appeal, plain folks, and bandwagon

Artists usually use musical imagery to make their compositions more unique and alive. imagery in music used to "show" music. because of that listeners feel what happens. they see music like complete composition. they hear sounds, they feel movement, they see a picture. it makes music deep. that's why  musical imagery is very important and is used by artists so frequently.