cross rate with bid-ask spreads Schweser p. 313 cross, currency, selling, because

svgleeson

hello,
Could anyone help to explain what the bullet points are telling us? I am confused at:
1) is this from a market maker or market taker perspective?
2) why is the first bullet point a bid “because you are selling the base currency”?
3) and if AUD is the base currency, shouldnt the pair written MXN:AUD, rather than AUD:MXN?
thanks for your help!
Suny