Should I keep the size S or M for this ribbed cotton top?

Please help me decide. ChatGPT is useless.

I wish to lose a little bit of weight and especially water (I kind of swell and retain water) so I am unsure which size to keep. It is 92% ribbed cotton and 8% elastan. ChatGPT it can both shrink and loosen...

Here is a comparison of these sizes. S is in the left column, M on the right.

Should I keep the size S or M for this ribbed cotton top?

Thank you!

Should I keep the size S or M for this ribbed cotton top?
Post Opinion