How To Spot Potential Verdigris Problems On Auction Photos?

Purchasing a coin which will then proceed to commit suicide by verdigrizing itself to dust is one of the last things a collector would want.

So what are the telltale signs that might suggest potential problems?

Here's a shop photo, for example (not resized or altered):



There are some pits along the rim, and some green stuff. The other side doesn't seem to have either.

Is it patina or is it problematic? How do you tell not having the opportunity to inspect the coin yourself?