Mobile-first online casinos are designed to work smoothly on your phone or...

https://wool-wiki.win/index.php/How_Do_Mobile_Casinos_Keep_Graphics_Smooth_in_the_Browser%3F

Mobile-first online casinos are designed to work smoothly on your phone or tablet. Using HTML5, they let you play right in your browser without extra apps, so games load faster and controls respond better to your touch