The flower on the left is what the right one will turn to as it ages, although, it, too, is beginning to wither. Besides looking pretty, Malva sylvestris is a fairly versatile plant. You can eat the leaves, raw or cooked, using the young ones as a lettuce substitute, while the flowers can be used to garnish your salad.
M. sylvestris can also be used for medicinal purposes. According to Plants For a Future (linked above), "All parts of the plant are antiphlogistic, astringent, demulcent, diuretic, emollient, expectorant, laxative, salve." The website also provides sources for these claims, which you can find in the "Links / References" section.
Disclaimer: Plants are living things. The Number Zero and all associated parties do not advocate killing plants, whether for ingestive, medicinal, recreational, or any other use. Killing plants is plant murder. The Number Zero and all associated parties acknowledge that killing plants is plant murder. In detailing the various methods of which one can dispose a murdered plant, The Number Zero is merely providing information and not endorsing these methods. By reading this, you are agreeing that The Number Zero and all associated parties will not be held liable for any misconduct that results from your reading of this article when the anti-vegetarians come and get you.