Every year, phone makers flock to Mobile World Congress to reveal their latest and greatest devices. At MWC 2025 in Barcelona, we've already seen some incredible new handsets headed to stores later this year, as well as concept devices we could see in the years to come.MWC occurs at a prime position: While Samsung always jumps the gun by announcing its phones in January, as seen with the Samsung Galaxy S25 series, other phone makers wait to tease their upcoming devices in late February or early March at the mobile industry's biggest event of the year.Many of these phones are cutting-edge but still conventional enough to compete with the Galaxy S25 for mainstream consumers. But in Barcelona, we also get to see the strange, inventive designs that phone makers are showing off. These have more specialty customers in mind, so not all will get wide releases.Admittedly, some of these are concept phones, which won't reach the market at all but, instead, serve as proofs of concept for intriguing ideas that could trickle down someday. Sometimes, it's a matter of technology needing to be further developed, or for novel components to become commonplace enough to be affordable -- we saw foldable phone screens at MWC for years before they arrived in market-ready devices.Here are the weirdest phones at MWC 2025.Detachable camera lenses on smartphones The Xiaomi modular camera concept. Andrew Lanxon/CNETNot one, but two phone makers have showcased new concept devices that have full-size camera lenses you can attach to the back of a smartphone.Xiaomi calls its concept the "modular optical system," which magnetically attaches the added camera lens to the back of the smartphone body. It has an even larger four-thirds image sensor (a size and ratio common on digital camera lenses) than the Xiaomi 15 Ultra's 1-inch type image sensor (which isn't actually an inch in size), connects to the middle of the back of the phone below the conventional camera block and takes pretty good photos, as CNET editor Andrew Lanxon found.RealMe also had a concept device with digital camera-size lenses you could attach. Unlike Xiaomi's device, however, RealMe's can mount full-frame mirrorless lenses, which are larger and could potentially take better photos. It also has an adapter that allows the mounting of professional-level lenses, like a Leica M11 or Canon R6.Foldable game console and triple-clamshell phone Samsung Display always comes to MWC with interesting concepts. Andrew Lanxon/CNETSamsung Display can reliably be trusted to debut exciting and intriguing concept devices at MWC. This year, the company's screen division had a couple ideas for future foldable handsets.The first is a foldable gaming console, which looks like a Z Flip-style clamshell foldable wrapped in a case with gaming controls on either side -- a thumbstick and a ring of buttons surrounding a hole -- but inverted, such that when the device is closed, the thumbstick fits in the button hole of the other. While we saw it run games, it's unclear whether this concept device is more of a smartphone with a neat case or a bespoke mobile gaming handset. Samsung's dual-folding concept was like a variation on the Galaxy Z Flip. Andrew Lanxon/CNETSamsung clamshell folding phoneSamsung also showed off a unique foldable we haven't seen before: a clamshell-style folding phone with two hinges. Even stranger, each folding limb was a different size, with a smaller flap on the top and larger flap on the bottom -- and when folded up, they don't fully cover the central part. Presumably, this is to ensure that both can fold inward and not run into each other, but it looks strange. Unfold each flap partway, though, and the phone does look a bit like the 90s cell phones that flipped down their thin mouthpieces. If you had to guess, would you say this is a phone from the past or the future? Katie Collins/CNETLastly, Samsung Display had a more unique take on its Z Flip clamshell series -- rather than the sleek modern look of last year's Galaxy Z Flip 6, the company redesigned its external display around a retro-futuristic look with polygonal gray plastic, a la Disney parks' Space Mountain or old PC and Apple computer housings. A stylish look for what's now a conventional foldable. The RedMagic 10 Pro Golden Saga edition. RedMagicRedMagic 10 Pro gaming phone and a silver and gold phoneThe $650 RedMagic 10 Pro gaming phone came out just before the end of last year, but there's a new version around. For nearly three times the price, you can get the same phone built with precious metals: gold-wrapped, with gold and silver plating in its cooling system, a carbon fiber body and a sapphire glass rear cover. The Golden Saga phone, as it's called, costs $1,500 for a fancier-looking version of the same gaming phone.There's also a Mora Pink version of the RedMagic 10 Pro if you want a more affordable version with just a bit more pizazz. Watch this: Samsung's Stretchable, Rollable and Foldable Screens Are on Display at MWC 2025 04:08