For me, the lack of colour is a problem. Everything in the room is bland, either beige or grey. Is it worth considering a more contrasty floor or bath panel colour, or darker shades? As it is, the wall panels just look like everything else in the room. I have no idea looking at the image what I am supposed to be paying most attention to.
Also I think some hint at 'practical' lighting might be to your advantage as no one has bathrooms as evenly lit as this, most bathroom light for safety comes down from the ceiling, yet the ceiling here is the darkest area and the floor surface is the brightest bit. No light at all seems associated with the ceiling in any way. So is it worth considering putting in fake 'practical' lighting as if from the ceiling and falling down the wall, to highlight the wall colour and any texture the panels might have?
Viewing this as a possible customer, I don't find the Vox photo remotely appealing either (so its maybe an industry thing rather than your photo thing). Ultimately to me neither of the sample images is selling a 'mood' or any sense of desirability or aspiration. Both images look bleak and on the cheap side.
Speaking strictly as a 'customer' I would prefer to see 2 photos of this product - 1 a well lit record shot of the panel surface alone so I could see exactly what I was getting and 1 of the panel in place with mood lighting, colour, accessories - basically show as part of a nice attractive bathroom I would wish to aspire to, rather than as something that looks like an easy clean public loo.
Having said all that, I think you are doing well so far in your attempts to replicate something similar to the Vox image and you are clearly getting there gradually. Well done.
The thing I would question most - is the Vox image the right image to replicate? Will an image such as that make people see these panels as desirable? Personally I think not, but thats just me. To me the VOX image looks done on the cheap, the product looks cheap - could your company use that negative aspect of a competitors advertising and make your own product look the better option?
I think before proceeding further I would be looking around at high end websites that sell bathrooms or bathroom tiles, looking for more imaginative and appealing sample photos to use for inspiration in lighting. Think product 'sexiness' or 'aspirational lifestyle'. Even people buying cheap products want things to look expensive and nice. Cameras lie well, so an expensive looking shot does not necessary have to be more expensive to produce.
I just did an ultra fast search for tiles and bathroom equipment and these are not the best images I am sure, but they are more engaging and show more interesting styling and lighting. Other searches could do better....!
http://www.toppstiles.co.uk
and for selling 'lifestyle' and good lighting effects
http://www.hugooliver.com/inspiration/styles/minimalist-bathroom-design
I also note after this quick look around, many site images do not show the entire room/entire wall in each shot. This would tie in with having a record shot of the panel, then putting in a 'desirability shot' of say the edge of a sink and a bit of wall panel and some classy accessory. This might help keep costs down as you could use lots of bits the same bathroom suite in seemingly different settings, can use fewer accessories over a greater number of images and it won't have the boring drabness of using the same room setting with just a different panel. People will get bored of looking at near identical shots over and over, doing bits of a bathroom will break up that issue.
As they say, sell the sizzle, not just the sausage.