Agreed, but that only applies to the L conductor. As plugwash said, I think BS1363 requires that the N, as well as the L, disconnect before the E - and, without playing around and trying to measure, I'm certainly not convinced that, in the photo you have posted, there is more slack in the E than in the N, is there by simple eye-balling, I would suspect that it's probably less)?Plugs do vary slightly but if one has the line conductor as short as possible then there is no slack in it and the other two are surely bound to be looser and pulled out later.
Kind Regards, John