The permanent Snow-Covered Plains is a basic land for the purposes of Eye of Singularity, since it includes basic and land in its type line. However, not all lands with basic land types are basic lands. For example, neither Mistveil Plains nor Temple Garden is a basic land, since basic doesn't appear in their type lines. A basic snow Plains card (such as Snow-Covered Plains) is no less a basic land card than Wastes is. See also this thread.
Edit: Now that I see the picture associated with snow-covered plains the answer is self-evident. Never mind, solved!
The permanent Snow-Covered Plains is a basic land for the purposes of Eye of Singularity, since it includes basic and land in its type line. However, not all lands with basic land types are basic lands. For example, neither Mistveil Plains nor Temple Garden is a basic land, since basic doesn't appear in their type lines. A basic snow Plains card (such as Snow-Covered Plains) is no less a basic land card than Wastes is. See also this thread.