It seems to be a rather common practice from OEMs to create a flagship phone and then, using pretty much the same design and build construction, they make a device with either a larger screen and possibly a few upgrades in its tech specs here and there with names like "plus", "pro" or any other moniker or, on the other hand, they create one with a smaller screen, typically downgrading a few specs too and calling it the "mini" version. Although users seem to prefer the larger screened devices and as a result flagships have been increasing their screen size year after year.
Meizu is a Chinese OEM that has been having a lot of success by offering high-quality products at prices that are lower than comparable devices from other brands. It might be a little soon to be talking about the flagships that the company is preparing for this year, but the rumored launched date was at the end of June, and seeing that the MX5 has been caught on camera matching the previous renders, the date might as well turn out to be true. This phone is supposed to sport a 5.5-inch display with Full HD resolution, so if we believe this, it's pretty safe to assume that the display of the MX5 Pro will be a little larger, the rumored screen size is 6 inches and it will probably have 2K resolution as its ancestor had this resolution already. Another possible feature is a fingerprint scanner integrated in the Home button.
Now, someone has supposedly taken a couple of pictures of the MX5 Pro, but the depicted device looks nothing like the leaked MX5. While the latter looks like it's made from a metallic unibody, the pictures show that the Pro version will be made of what seems to be a metallic frame surrounding the device and what looks like glass on the back cover. The camera is located on the same position, but it seems to be a little smaller and the flash, which is hard to tell, but it seems to be dual toned, has changed a little too. It looks like we will have to wait a little longer to verify this information.