No source. Assuming that the imagery is well geo-referenced. This building's footprint should be moved to the NW, because even though the building is casting a shadow on itself, it is possible to see both its North and West sides from this imagery. You are mapping the building's footprint i.e. where its walls touch the ground. Although the roof can help you to get the right shape you are not mapping the roof per se. 

The parts to the SE of the roof should be added before the entire footprint is moved to the NW. You added an unnecessary node to the SE of this footprint, and in this case it appears that it will result in that wall not being straight when rendered on the map. Please press q to automatically square the corners of buildings as it more practical and accurate than drawing 90 degree corners by eye.
            ---
            
            Published using OSMCha: https://osmcha.org/changesets/152917172
            