How are appraisals done without access to the house?

[Sam Tright]

My HML requested an appraisal. Cost $500 and I provided an itemized list of repairs, along with pictures. I was not asked for the lockbox code (i don't have it anyways, the seller's realtor does)

Curious how these types of appraisals can be accurate. Pics can be misleading or omit damages. The exterior can be walked curbside, but probably not the rear. Have you guys found them to general be on target?