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I don't see how that bridge on the picture could be destroyed very quickly no. As others have pointed out (but you have ignored): JRRTs paintings often contradict his written depictions when it comes to detail. Clearly the bridge on the picture can't be "cut", which is what Bard cries out for in the book. The bridges (note the plural form) JRRT had in mind when he wrote the passage in the book therefore must have been different bridges to the one he painted at another occation.

Tolkien wrote that the bridge or bridges were destroyed quickly and personally I have little difficulty imagining it being done. "It's easy if you try", in the words of John Lennon. Why would you deny yourself the pleasure of it making sense? Or do you perhaps find it more enjoyable to ignore everything that doesn't correlate with your own narrow interpretation of the passage.

And btw, the distance between The Lonely Mountain and Lake Town was rather significant. Although they had little time to destroy the bridge it wasn't a matter of seconds. I would imagine to took Smaug a fair bit of time to reach the town even if he was travelling quickly.