A florist sells a range of products including flowers and an assortment of small gift items e.g. picture frames, essential oils, candles, oil burners, lanterns, gardening magazines, handmade chocolates, picnic baskets, fresh teas, and novelty mugs. During Mother's day, the florist focuses on Mother's Day flower arrangements and experiences its highest weekly sales of all flower types, but this week also has the highest weekly sales of handmade chocolates and picture frames.

Why do non-promotional sales items like the chocolates and frames experience uplift during the Mother's Day sales promotions?