TikTok's Photo Mode — launched as a direct competitor to Instagram carousels — lets creators post up to 35 still images that viewers swipe through, each displayed for ~3 seconds before auto-advancing. The format has exploded because it combines TikTok's discovery algorithm with the swipe-through engagement that carousels generate on every platform. But the format's success depends heavily on the first slide: if the cover image doesn't communicate what's inside, viewers swipe past without ever seeing your content. A photo grid cover solves this by previewing your carousel's content in a single frame. The most effective TikTok carousel grid strategies: a 2×2 cover grid that shows four thumbnail previews of images inside the carousel — this tells viewers 'swipe to see these in full' and dramatically increases completion rates. A 1×3 'teaser strip' showing the beginning, middle, and end of a transformation or sequence — viewers swipe to see the full progression. A 2×3 'chapter preview' for tutorial carousels where each cell represents a step or topic covered in the carousel. For the grid itself, export at 1080×1920px (TikTok's native 9:16 vertical format). Use 4px cell spacing for clean definition between preview thumbnails. Add thin cell borders (1px) so adjacent images with similar tones don't visually merge on fast-scrolling feeds. For tutorial and educational carousels, add number overlays (1, 2, 3, 4) to each cell in a separate editing step before importing into MergeFrame — numbered grids consistently outperform unlabeled ones for educational content. The key metric to track: swipe-through rate (STR). Creators using grid cover images report STR improvements of 25–40% compared to single-image covers because the grid communicates content depth immediately. MergeFrame's local processing is ideal for TikTok creators — pre-release content, branded collaborations under embargo, and personal photos stay entirely on your device before publishing.