I'm not sure who talked about an HDMI monitor.
If you want to display the Pi's startup in a MacDo, you can
1- power the Pi fro your laptop's USB port (well, from *most* laptop's USB port, the Pi takes a bit more than the USB standard states, but so do USB hard disks, so most laptops can handle that)
2- SSH into the Pi via a Pi-to-Laptop wired ethernet connection, that way you don't have to mess with MacDo's Wifi
3- Connect some interactive hardware, like LEDs that you can make flash, to the Pi, to that the Pi is not just seen via a window on your laptop, but actually does something on its own.