There are lots of ways to continue. For example, the red box above the "7" must contain 2 filled squares. This means that the "8" is already missing one square and thus the blue box must have all 3 squares filled in.
The green box above the "7" can only have 1 more square filled in. This means that the "8" in the green box is already missing one square and thus the orange box must have the 2 squares filled in.