There are the two "Flying Motorbike" signs clearly visible. These would have been visible even with the taxi there. In addition to the two signs, the council have done more than the regulations require by also adding in a large flower tub barring your progress with the same sign. Sorry to say it, buy I cannot see anything at all that would form the basis for a credible appeal at London Tribunals unless the PCN contains a fatal error of content. Clearly you didn't know what the signs meant. They are now in use all over London ! They are used instead of No Entry signs because some classes of traffic are allowed to pass, like buses.
Please post all the other PCN pages so we can check them for errors. PCN errors have won many appeals in the past, although you'd have to go to London Tribunals, as councils almost never admit error.