I have never seen shellac look like that. It looks more like shellac wax, which is the waste from dewaxing shellac. However, that could just be the bag.

Blonde shellac is fine for seal coats, it is probably going to end up being clear but will block tanin bleed. You can use alcohol based dyes to change the color of shellac, Transtint works great but if you are not worried about colorfast shellac, any aniline dye dissolved in alcohol will work.

Good luck

Thanks! We just need some shellac to block tannins in the pine and to go over the knots. After we will put an white primer paint (it doesn't have shellac in it) then paint it with white chalk paint.

To answer your question on the title, that doesn't look like either stick-lac or seed-lac to me. I also don't think I could process stick-lac into seed-lac if it was.

Sticklac - You can see it is not smooth and even...

Seedlac - After the lac has been scraped and the lac beetles and wood branches have been removed.

shellac wax which is the waste from dewaxing...

I am certainly no expert on processing shellac, I never even use seedlac and usually buy waxed, and dewax it to varying degrees myself, or dewaxed flakes. However, to my eye your picture looks more like shellac wax than shellac.