Sony Xperia Cosmos expected to be launched as the Xperia C4
Right now, we don't have too many details about the features of the Cosmos / Xperia C4. But we know that it's going to run Android 5.0 Lollipop, and should be powered by an unknown processor made by MediaTek. Also, as you can see in the images below, it's obvious that the C4 has a large front-facing camera with LED flash, but it's not clear if this is a 5 MP one, to match the one of the Xperia C3 (it could be one with a higher Megapixel count).
Like the C3 (pictured above), the Xperia C4 is probably a mid-range device, so it shouldn't cost too much. While Sony didn't confirm anything regarding the C4, the new handset might be officially introduced in the coming months. The Xperia C3 was announced in July last year, so maybe the C4 will be unveiled around that time this year. We'll let you know when we hear more on this.