After a Pokemon hatches from an egg will it show a shiny model, or will it look the same as a non-shiny Pokemon?
It will look shiny immediately if it is shiny. You will not see the sparkles though as far as I can tell. I only hatched one shiny myself. For pokemon that may be very similar you should probably also check for the marker in the pokedex unless you know what to look for.
This video for example shows a shiny Honedge hatching. It's animation was otherwise the same as usual.