It is recalling the previous day's gifts, so you know just how amazing their true love is. If you didn't repeat them on subsequent days, no one would remember the pear tree by day 12.

Unfortunately MAL just says source as the original concept. While Mushoku Tensei IS originally a light novel, the anime is based on, and made to sell, the anime adaptation that had already been in print. This is probably true for a lot of items in this list, as using anime to boost manga sales is very common.