Where social media is concerned, there are a few pillars that represent the majority of users, and Instagram, is one such pillar. Having risen to the top by offering users a very mobile-focused experience, as well as partnering well with already popular service Twitter, Instagram has become one of the most used services on mobile after Facebook - which coincidentally owns Instagram. The photo sharing service was not always native to Android, and for a long time it was only available on the iPhone, that changed some time ago and now Android has become a massive part of the overall community. The developers have now bought a new feature to Instagram from the iOS version; 3D Touch.
When Apple released the iPhone 6S and 6S Plus, they had to put at least one new feature into a device similar to the previous model, and so they chose 3D Touch. Essentially just a pressure-sensitive touchscreen, the new feature allowed apps to gain sort of right-click context menus and more without making users open up another menu, but merely press harder on the display. For Instagram, this meant a pop-out of a particular photo in your feed or from a profile, and keep your finger pressed to "hover" over like and share buttons. They've now bought this feature over to Android, of course as there are only devices from Huawei with pressure-sensitive touch (and a questionable implementation of it at best) this feature works using a long-press. If you've used the iOS version of this feature it's not going to be as satisfying as it is on an iPhone, but it's a nice addition on Android nonetheless.
We haven't seen the update go live win the Play Store just yet, but we're sure that Instagram is working hard to roll out the new feature to all of their users. It would appear that the vision of the app you're looking for is 7.13.0 and it should be rolling out to all users soon.