Thanks to a pretty wretched blunder, LG inadvertently revealed its upcoming G4 smartphone on its website ahead of the handset’s April 28 unveiling.

The device looks a lot like last year’s G3 with a very attractive all-glass front and super slim bezels, but LG has added a stitched leather back that will almost certainly put some fans off.

The images appeared on an official LG microsite over the weekend, so we have no doubts about their authenticity. Specifications were posted alongside them, but we’re going to ignore those because they were obviously placeholders; they didn’t match up with the information LG has already revealed about the device.

What they do confirm is the G4’s new form factor, which sports a trademark LG design with rear-facing buttons, a laser autofocus sensor alongside the rear-facing camera, and a buttonless front with beautifully slim bezels.

The back of the device isn’t quite as attractive, however.

Six variants of the G4 come with colorful leather backs. But they aren’t classy leather backs like those you get with the new Moto X; they have tacky, unnecessary stitching that runs right up the center of the device.

It’s not quite as bad as the faux leather backs Samsung shipped with the Galaxy Note 3, but it’s not far off. Personally, I’d much rather have a device made of plastic and that add a simple leather skin or case.

Fortunately, it seems LG will offer plastic backs, too. Three of the devices seen in the picture above have a plastic back with a patterned finish that looks very nice.

It’s unclear how you’ll choose between these devices, because LG almost certainly won’t be making all nine options available through carriers and retailers. Perhaps the company will take a leaf out of Motorola’s book and sell the leather options via its own online store.

Another leaked G4 image reveals its new Camera app, which comes with a whole bunch of manual controls, and the ability to shoot RAW images.

There’s just over two weeks to wait until LG’s G4 event, so if you’re a G-series fan, you have to be pretty excited. Like the G Flex 2, the G4 is expected to come with Qualcomm’s latest Snapdragon 810 processor, as well as 3GB of RAM, and a 5.5-inch Quad HD display.

Thanks to LG’s recent teasers, we already know it will have a 16-megapixel rear-facing camera with a new f/1.8 aperture that should result in significantly better low-light photos.

• SourceEvleaks