Why destroy Laketown's bridge?

[Sauron the White]

from Rikae

Then, Sauron, you are still arguing that the picture is misleading; as it not only depicts a bridge that doesn't look as though it can be cut, but one that doesn't look as though it can be destroyed in "little time" at all, something the text tells us was done. So, any way you slice it, either that bridge was destroyed (and the picture is misleading), or it was not (and to make this assumption reasonable, we'd need to explain why only some bridges would be destroyed).

The picture shows what it shows. Period.
The text says what it says. Period.

If JRRT says the bridge was destroyed, then it was destroyed. If he says the townspeople have very little time to do this in, then they had very little time.

If the description of the bridge and the illustration of the bridge clearly show a bridge which probably cannot be destroyed in very little time - then who is at fault?

Wait I know the answer to that one: ME for pointing it out.