It will lose some of the lines, like the roll of the arms won't be as pronounced. Part of the question is - how tightly fitted do you want the slip cover to be? And do you want it to cover the legs all the way to the floor, or partially, or not at all?

Having a separate seat cushion will help it from looking like a total blob.

I once made slip covers for chairs with rolled arms. The part around the rolled arms was snug and I used piping just as your current chairs have that helped to delinate the lines of the chairs. They looked fine.
Diane

Yes it can be done and look nice. If you're having it done by a pro, ask to see photos of their work. They should have a book you can leaf through with befores and afters.

That said, I think the fabric on the chairs is cute and if my monitor is correct on colors, they go well with your walls. Of course, washable slip covers are sooo smart with kids and dogs or sloppy adults in the house, and certainly if you entertain a lot.

If you want to make them yourself, here is an online tutorial for you:

Here is a link that might be useful: How to Make Slipcovers - A 6-part video series