The portfolio is the product and the performance problem at once
Photographers are the one client group right to want enormous images, and the group punished hardest for having them. A gallery is dozens of high-resolution files, and a phone on a weak connection abandons before the second one paints. It is solvable — modern formats, sized variants, real lazy loading — but it has to be designed in rather than patched later. A slow portfolio reads as an unprofessional one, unfairly and immediately.