The relevant phrase is "make/making a purchase". "what looks like" and "routine" are insertions.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
Hans51This customer is making what looks like a routine purchase through Amazon.com.You can substitute the structure 'what looks like X' for 'X' in many cases. Other substitutions you'll see are 'what seems to be', 'what we call', 'what we might call', 'what is called', 'what is clearly', and so on. There are many variations. The whole structure, starting