Inaccurate placement of marker

I try to use the new feature to "Sync viewer and map markers" to tag a playground on OSM.

Image key: jYNjmv7P567FSw92Z1_DEw
User: tordans

Testing application: https://bl.ocks.org/tordans/339312be319c977a4485a6f56c9800bc

The issue:

I placed map marker on the foot path that is on the playground. I did this on several images. The Markers all show up somewhere else on the map.
In the last case, the image alignment seems to be completely off (see red arrow).

Expected behaviour:

• only images are available that actually align with the surroundings
• the map marker that I place on the same street actually show up at a very similar position when placed on multiple images
• maybe the problem is, that I only have yellow GPS accuracy (color of the icon in the app when taking pictures) … but this is the default-quality inside Berlin and also something the app should handle internally

Screenshot