The particularly high-heat re-entries of manned capsules, the Space Shuttle, and so forth are unpowered; the atmosphere slows the spacecraft down. The Falcon 9 first stage re-entries are powered; three engines light to slow it down. The physics of how this works are complex and a bit counterintuitive, but the upshot is a thermal environment which isn't as brutal as an unpowered re-entry.

Beyond that, the glass in front of that camera's probably formulated to take extreme heat.

And of course, as jdblair points out, it's starting at a slower speed to begin with; faster than just about any aircraft (except maybe the X-15), but well short of orbital velocity.

Its not just re-entry that makes heat, its re-entry at high speed. The first stage wasn't in orbit. I don't think it had reached orbital velocity and it turned around and fired its engines to reduce its speed even further.

Re-entry from orbit wouldn't just destroy the camera, it would burn up much of the craft as there is no heat shield.