Yes. This is a reference.
Anyone who hasn't seen Back to the Future needs to watch it. Now. Seriously, go watch it. It's awesome.
Tia and Luna are probably gaping at a time traveling Dolorian from an alternate dimension with Marty and Doc inside. Yup. Someone needs to write a fanfic.
Anyhow, the idea for this pic popped up in my head one night so I drew it on paper, scanned it, vectored it in Illustrator, and shaded it in Photoshop. :3
For those who don't get the reference, here is a musical remix of Great Scott and This is Heavy: [link]