Why does it have an l-tag for each decimal point in both lat and lon coords? Is that how the geotag nip work (I haven't read much about it)?
I don't know either. My guess is that's for very laze search mechanism. It's especially useful for geohash, so you can look for other pictures in the same small / wide area. Maybe less so for lat/lon. https://www.pubnub.com/guides/what-is-geohashing/