In this changeset, you modified the way representing Palisades Apartments to connect directly to the adjacent sidewalk. This means that if you add or remove nodes from the sidewalk, it changes the apartments too, and vice versa.

Before this edit, the way representing the apartment complex had 8 nodes, and now it has 17. If a user downloads the new version of the data it will be almost twice the size.

What I mean by topologically incorrect is that the sidewalk way is supposed to represent the middle of the concrete area, and the apartment complex goes to the edge of the concrete. If they touch, it implies that half of the sidewalk is part of the complex.

Also, if a crosswalk were built, and you added a node to the sidewalk to accommodate it, then you would end up adding it to the apartment complex as well.

If you are not already, you should disable most of the map features while editing, using the Map Data tab.  Only edit the ones you want to touch. It is common for new mappers to accidentally touch features they did not want to edit, and it can be overwhelming and slow down the browser if a place is mapped in detail.