Can you explain, what happened to the surface of the spacecraft?
Foam insulation, applied during construction, similar to the orange TPS on the main core stage.
Was it burned mildly like when you try to peel of coating with a heat gun?
You are looking at the interim cryogenic propulsion stage ICPS:
The ICPS is based on the five-meter-diameter version of ULA's Delta Cryogenic Second Stage (DCSS) that has flown 24 times on Delta IV missions since 2004 with 100 percent mission success.
ICPS features a slightly larger liquid hydrogen tank as compared to the Delta IV second stage, as well as electrical and mechanical interfaces specific to attaching and supporting the Orion spacecraft, and a second hydrazine bottle for additional attitude control propellant.
The DCSS cryogenic tanks are insulated with a
combination of spray-on and bond-on insulation,
and helium-purged insulation blankets.
The above information likely covers the internal insulation, the outside insulation looks a lot like a trimmed or shaved version of the TPS that covers the core stage and skirt but is painted white, and not left the orange color seen on that stage.
Overall TPS foam information:
There are three different types of foam applied to different parts
The “net spray” leaves a textured surface on top called the “rind”.
“Net spray is ‘as applied,’ so it’s got that rind material on it,”
“That bumpy surface, that’s the rind and so ‘net spray’ just means that rind is still left on. And either trimmed or shaved would be where we take that rind and we remove that rough section of it.”
You can see the texture was there before launch: