Comparison of two smartphone models, sd 1.5, sd 2.1, side by side, white background, detailed screen display, sleek design, metallic edges, rounded corners, high-gloss finish, camera lens, flash, volume buttons, power button, SIM card slot, USB-C port, headphone jack, 3/4 composition, softbox lighting, shallow depth of field, product photography, studio setting, clean and minimalist atmosphere.