Success on the former suggests better inherent ability to interpret space, whereas success on the latter suggests greater ability and patience to simply copy what you see. My guess is the former (life paintings). Don't take my word for it.

This is a silly way to frame a question.
Is it a good painting? Is it something you want to say about yourself? Does it complement or supplement some other aspect of your portfolio? Does it show a positive quality about your abilities?
You're not a better architect if you can paint a building and you're not a better painter if you paint every brick in a wall.

It's your ability to show abstraction and imagination within your paintings that become important and so closely associated with architecture. I don't think your ability to "copy" a still life is as, or at all important.

^ That's not completely true. Spatial awareness and interpretation tends to be prioritized over abstraction. Painting a building represented by simple colored squares (like Piet Mondrian) is certainly abstract but it is definitely not suitable as an evaluation of one's potential success in the field of architecture. Of course, they don't just want to see you "copy" buildings either. They want a mix of spatial awareness and imagination, but the former is prioritized over the latter. This isn't art school.

paint as you want to paint. don't worry about pleasing anyone.

schools aren't looking for any particular style, just evidence of inquiring mind, etc...