English is written left to right. Hebrew is written right to left. We know that. Browsers (for the most part) know that too, just like they know that the default directionality of a web page is left-to-right (LTR), and that if there is a setting that explicitly defines the direction to right-to-left, the page should flip like a mirror. Browsers are smart like that. Mostly.
But even browsers have problems when deciding what to do when languages are mixed up, and that, my friends, is a recipe for really weird issues when typing and viewing bidirectional text.