As the number of YouTube users continues to increase, various studies have examined thumbnails with most studies have focused focusing on their technical aspects. However, research on user preferences for thumbnails in thumbnail- related content remains scarce, highlighting the need for a differentiated approach to promote beauty content. Therefore, this study aimeds to examines the current usage patterns of thumbnail-related YouTube content and identifies the preferred thumbnail elements and differences across age groups. A revised questionnaire was developed based on previous studies, and a survey was conducted between October 1 and December 1, 2024, targeting female residents of Jeollanam-do and Gwangju, South Korea, from their teen years to over age 50 those. The final analysis included 300 completed responses included. The research findings revealed significant differences between among age groups in four categories: typography, typography layout, number of words, and thumbnail composition elements. These results, indicate that designing thumbnails to reflect the preferences of different age groups may enhane user satisfaction and serve as a useful strategic resource by a providing clearer direction during content planning. In particular, because thumbnails are the first visual elements users encounter on the YouTube platform, incorporating preferred ele- ments into thumbnail design may positively influence click-through rates. This could naturally lead to the acquisition of new sub- scribers, increase engagement among existing subscribers, and ultimately contribute to higher view counts.