Was trying to draw a powersuit Lyra at first, and then I thought it'd be neat for her play a protector role. So I just sketched tons of suits in various poses, then eventually abandoned the whole Lyra thing shortly after the kneeling one came up. i.imgur.com/0XAjJ5y.png
Past that, I think it's fair to say that it was just sci-fi stuff in general.
Wonderful little details everywhere (the little spots everywhere, the shading, etc), Luna and Celestia looking sweet as can be, and best of all, an awesome sci-fi mecha and pilot gently allowing the ponies to approach~
Dear artist, your skills are amazing and I'm now going to check out your no-doubt amazing gallery~
(Listen to this while you read www.youtube.com/watch?v=H1K3OJ… ) My headcanon is that this is a human robot pilot who got lost in dimensions or crash landed in Equestria somehow. He can't leave his suit or he'll die, as the air pressure and atmosphere in Equestria is far different from that of Earth. His suit only has about 30 days of life support left after he lands. In this picture, he has become dear friends with the two princesses, but his suit is nearly through its reserve life support systems. He is dying. This is his final goodbye to them. He has had the greatest month of his life despite it being his last. He thanks them for their friendship, and they sit in silence, enjoying the end a short but amazing friendship between intelligent beings from different corners of the universe. After his passing, the princesses will forever remember him as a reminder that friendship exists not only in Equestria, but throughout the universe.