Find my location on iPhone is a mess

Find my location is very strange and I have a few questions.

a) is it normal for a location to randomly jump next door or to an apartment building across the street? If this was a daily occurrence, it would seem less weird, but this was an isolated incident. Happened randomly one day then never again.

b) is it true that the smaller the blue dot, the more accurate the location? The dot seems to get very small when the person sharing their location with me (call it an employee) is “next door” or “across the street” at an apartment complex

c) why is the blue dot separating from the “friend’s” actual picture? For example, it will show the the blue dot (with a white circle around it) across the street in a random apartment building, but the contact’s actual image/picture will be in the place they’re supposed to be?