Strabismus is not necessarily crossed eyes. Crossed eyes are Strabismus but Strabismus includes Walleyes, where the eyes look to the outside and other types where one eye looks straight ahead and the other might head off in another direction. I went to school with a girl with this latter. We used to joke she could watch two boys at once.
Sometimes the condition is only evident when the person tries to focus on something but when relaxed the eyes look normal.
If anything I think your kitten (cutie-pie, sweetie, precious little thing) has walleyes, not crossed eyes. If you were planning to show this kitten then you should contact the breeder. Also ask your Vet but it is sometimes outgrown. That case looks very mild but ask your Vet if it might impair the kitten's life or get worse. I can't see (
) how it would be severe enough, from what I see now, to be a serious life threatening thing in a pet kitten. In a wild cat, yes, might affect ability to catch prey.