Probably all tags except highway=street_lamp and bin=yes. They seem to be copy-pasted from a specific node. I'm not sure about all nodes, but I've checked a few nodes and it seems it's like this for all nodes modified.

The added tags include traffic_sign=* tags for a direction sign to Kallahdenniemi and a cycle-footway sign. This was one thing which raised suspicion as there are no signs like these at a park near me where the edits have been made, as the location on the direction sign is in a very different place. I started to wonder, "why there is signs like this?" :D