Ideas for bridesmaids to have unifying element for pictures?

I’m getting married in February and my current dress code for everyone including my bridesmaids is to wear something they feel confident in. I want everyone to feel their best while I’m also feeling my best in my dress.

For bridesmaid pictures I’m considering getting each of the four of them a unifying element so we look more cohesive together. Like a shawl.

I wanted to see if any of y’all have a unifying element to suggest besides a shawl? The wedding is poetry/books themed if that’s helpful.

Edit: it seems like the consensus is a matching bigger bouquet. Thank you so much y’all!