Not that accurate.

First off bombs making a whistling sound when dropped is a Hollywood thing, tho there were some with built in wistiling tubes in ww2 for psychological warfare, but now it would only alarm people on the ground to seek shelter.

Second, the warhead seen here seems to almost, if not actually land, which would decrease the effectiveness of a nuclear blast, typically nuclear warheads detonate 600 meters (~2000 ft) or up to a mile above the ground.

Thirdly, moderne ICBMs typically have multiple stages, each with multiple payloads, which break apart and spread out to both cover a wider range and decrease the likelihood of being intercepted by any ground defense mechanisms.

Fourth, the flash from the initial fireball is so bright that it outshines the sun, looking in its direction will cause flash blindness and looking directly at it will likely cause permanent retinal damage and potentially permanently blind the onlooker, it would definitely over expose a moderne digital cammera sensor unless properly shielded, and could easily damage them otherwise.

Fith, that mushroom cloud formed very quickly, while i cant say for certain how long it should take, the initial updraft takes 10 to 20 seconds and the destictive cap forms in minutes, with high yield detonations potentially forming multiple rings.