Obviously was a smartphone, given by the extraterrestrials who helped constructing that temple and pyramids.
PS. If you ever get the chance to compare parts of Cambodian hinterland (eg. area around Battambang) with South India (eg. western Tamil Nadu) you will realise they bear a striking topographic resemblance: vast tropical plains punctuated by extremely vertical mountains. Beautiful setting for settled agriculture.
I think that particular stone carving was recent(ish) but might be wrong. It was a very small local wat and I think I went into it randomly while walking around - the depiction didn't felt buddhist nor hindu at all, if anything it looked masonic or automatically generated from a set of symbols.
[0]: https://en.wikipedia.org/wiki/Yajna
[1]: https://en.wikipedia.org/wiki/Vedi_(altar)
[2]: http://ijyr.dsvv.ac.in/index.php/ijyr/article/view/50/101