No. There is nothing on the MemberMouse end that will be done to change the look of your PayPal landing page.
With that said there are two things to note:
1. The PayPal account you have can influence the checkout page used on PayPal. As it's a PayPal feature, we are not clear on how this works but we can say that older PayPal accounts will use different pages then new ones.
2. PayPal processes one-time payment differently than subscriptions. One-time purchases will go to a checkout page on PayPal that's significantly different than the one for subscriptions. The reason is because with a subscription, a PayPal account is required. With a one-time purchase, it's not. You can attempt to purchase a one-time purchase product and see the difference.