Since they'd moved into the city, Ultra Magnus had been sending out his holomatter to try and familiarize himself with the human culture at large. Usually this just meant walking around scrutinizing everything. So while most people might not have noticed, the flickering holomatter avatar, to someone as detail oriented as Magnus it was hard to ignore.

While it was possible an Autobot had arrived on planet and either been too irresponsible or incapable of reporting in, with an unknown number of Decepticons on the planet, it was better to remain cautious. So, rather than pinging the signal or confronting them straight away, Ultra Magnus was hanging back, watching with a healthy amount of suspicion.