Just Guess the stage.

Well I'll just make my guess and say it is A Private Rainforest. All 4 units would be viable to a certain degree, Cadaver Bear would be a fair reason to bring Sniper the Deadeye, as you CANNOT let him connect to your base. There are no enemies in this stage (besides Cadaver Bear himself, whom you can Holyblast), that will be able to reliably kill Sniper the Deadeye, the stage does have the shown background, and you may not have to worry about knocking back a Brollow since Cadaver Bear is there to take the hits, and there aren't too many of them, except after base hit, which isn't forced. I wouldn't say it is likely since Shigong Cat isn't in the photo, Courier Cat and Can Can Cat may not be particularly amazing in this stage besides killing Brollow, and the stage doesn't usually last so long that you can get 3 Sniper the Deadeyes.

Kuyerpip

CORRECT!!!!!