Organic Potstickers Vegetable

From the photo (looks delicious btw) the cabbage pieces are large enough to be an insect issue. So I would have to say not acceptable.

For a product like this to be kosher, would the company have hire a mashgiach to visually inspect all the vegetables for insects?

In this product the offending item was cabbage.
Theoretically if a company would get certified by a Hechsher that is expert in removing the insects and a process would be set up whereby the cabbage would be bug free, then the mashgiach would not need to visually inspect each piece.
But of course that a lot of ifs.

What about the fact that it’s frozen?

Freezing vegetables does not help with regards to the insects. Frozen vegetables must also be bug free.