Let lambda>kappa$\lambda>\kappa$ and coll(kappa, lambda)$\operatorname{Coll}(\kappa, \lambda)$ be the poset collapsing lambda$\lambda$ to kappa$\kappa$. Pick a subposet P$P$ which is $\lt\kappa$-closed and of size lambda$\lambda$. Can we say that P$P$ is forcing equivalent to coll(kappa,lambda)$\operatorname{Coll}(\kappa,\lambda)$? Or, more generally, which are the minimal conditions to make P$P$ equivalent to coll(kappa,lambda)$\operatorname{Coll}(\kappa,\lambda)$?
When lambda=kappa$\lambda=\kappa$ (i.e., kappa cohen$\kappa$-Cohen forcing) I am pretty sure that this be true, so I was interested in understanding whether it generalizes.