Shinny covered the main points well, and yes many schools seemingly ignore the analysis of visuals in spite of this being a fixed part of every exam. When you analyse a visual you begin by looking at the things you see plainly before you. So the writing and the image of the half-caste figure. You can then go into a lot more detail. This is especially critical in your end of year exam where the visual is something that the examiners really hope for you to cover.
As Shinny mentioned, the body of the half-caste is coloured in earthly colours. This can also be extrapolated to the background. The orange background, which almost has a wooden feel to it, also harkens back to the roots of Aboriginal culture. The use of this colour ensures that the contents of the image are considered to be inextricably linked to Aboriginal culture, and thus reinforces the suggestion that a person with fair skin can still culturally be very much an Aboriginal person. The font and the shapes in which the letters are embedded also strengthen this feeling. You might also want to look at the use of 'black fella', a term that is more often heard amongst Aboriginal communities as a descriptor of individuals of Aboriginal background. By saying 'black fella', one implies that the half-caste is regarded by the Aboriginal community as part of their community, in spite of their 'fair skin'. This further sways the audience from the view that skin colour is a critical part of identifying oneself or being identified as Aboriginal. Finally, you might also want to look at the person in the image in a little more detail. The face presented is heavily simplified, with small eyes (encircled with black shadows) and no mouth or ears. The effect of this is to strengthen the sense of sympathy engendered by the image (which shinny has already mentioned), by portraying the half-caste as an almost pitiful and slightly lost figure with no voice and a blank expression. It implies that the reality of the fair skinned Aboriginal is being ignored.
Hope that helped!
I also like how they turned the A into a body and legs for the guy, but that's something you probably wouldn't mention
