Well, earlier when you tapped on a YouTube link while on WhatsApp you were kicked out from WhatsApp and taken to the YouTube app where you could watch the video and then switch back to WhatsApp. All this was somewhat time-consuming. Once the update rolls out all you have to do is click the link, and the video will start playing within the app itself in picture-in-picture mode. This means you can continue the conversation and watch the video simultaneously. You can also switch between different conversations without pausing or closing the video. The update is still only limited to iOS and does have a few bugs and glitches that would need to be ironed out, and those will be taken care of shortly according to reports. So we can expect WhatsApp to take care of these minor issues and then continue progress with the Android update of WhatsApp as well.