Hello, you did a good job appropriately deleting the footprints in the NE, however the building footprints you added are not as accurate as they could be, and you even reduced the accuracy of an existing footprint here. This is mostly becasue you're including the Walls of buildings visible in the imagery as its taken from the West. 

When mapping with imagery captured at an angle, please position features where they are at ground level. You can map the outline of the roof and then reposition the building to the base of the walls. I recommend you watch this [video about mapping dense urban areas](https://youtu.be/JAPiGntG6fs) and read this [written guide](https://wiki.openstreetmap.org/wiki/Roof_modelling#Typical_errors_in_the_interpretation_of_roof_geometry_from_aerial_images).

See how I mapped some of the footprints in this area in https://osmcha.org/changesets/172440180

Thank you for your contribution. If you want to experience the OSM community or to get timely feedback from other mappers; I recommend that you attend a mapathon. You can find events here https://osmcal.org/