There are some visual differences that you can spot at a glance. For one, the front set of life boats on the Oasis are 5 together, then a space and the last on. The Allure are grouped 4 and 2. Also, the high rise section in the Aqua Theatre is dark/black on the Oasis and is white on the Allure. You can tell which one is the Oasis by looking at the water line too. The Oasis is off on a cruise fully loaded and sitting lower in the water while the Allure just has crew and not all the plants and other items yet. But, who's paying attention to that trivial stuff, that is a gorgeous picture of what 2 Billion+ dollars looks like floating!!
We can't wait to go on one of them if they will ever come down on the price premium.