This defect is often referred to as tombstoning, draw bridging or Manhattan skyline, particularly if there are many parts all standing vertically.

The defect is caused by uneven wetting where one termination solders before the second causing the surface tension of the solder to pull the device in one direction. It can be exaggerated by the amount of paste on small parts, 0805 chips and below or incorrect pad sizes increasing movement during reflow.