I don't know about what exactly, but she's definitely having a think.
On these cool days she will sit like that on the front porch for an hour or more. Just looking out over the prairie and glancing back and forth across our yard, her brush piles, the cottonwoods. After a while she'll get up and either take a walk into her domain or come to the door and bark for me to come and let her in.
I'm inclined to think that dogs do indeed have a rudimentary esthetic sense. Last summer I lost my Rottweiler, Murphy, to bone cancer. He was probably the most esthetically inclined four-legged I have ever known. He had a pad on the front porch and at dusk he would want to go out and lie on the pad and watch the sunset. I would go out and sit on the steps and he would put his big head on my leg and we would watch it together. When we would travel or go camping he also demonstrated a liking for streams. He could lie along a swiftly moving stream, watching or peacefully snoozing, for so long that I would have to find him and make sure he was all right. The pleasure he took in these times was plain to me. I miss him very much.
So I have no doubt that Emma is also having a think. Perhaps not as deep as Pascal's nor as incisive as Voltaire's. Nevertheless, I respect her pensive times and try not to intrude too much.