Maybe they have not put the decals on just yet. I’m pretty sure the new rules call for more visible numbers, so the only thing I can think of is that the teams have been so preoccupied with preparing their cars that putting numbers on is a minor detail.
Also, you can clearly see the number in the top-down shots of the Lotus.
There is ample opportunity for the numbers to be displayed on the flat surfaces on the nose now that the steps have been taken out of them.. along with being on the helmets as per the rules.
Chilton chooses #4 – the highest he’s come in a junior ladder championship, although he was lucky both times. 2009 British F3 – Ericsson would have battled for the title with Ricciardo, if he could’ve driven a full season (did so in Japan instead and won there). 2012 GP2 – Calado unwell at last race, and possibly Van der Garde and even also Leimer could have been ahead of Chilton at season end, if luck went another way.
Frijns must be looking for Valentino Rossi comparisons..