I've been working with CRM since version 3.0 and I have seen drastic changes to the CRM UI with every new major release. Similarly, this service update also brought new UI changes to Dynamics CE users. If you have already worked with the earlier version, you might be aware of the frustrating amount of unnecessary spaces on the entity forms. The new UI has removed the unnecessary spaces and improved the fonts.

In the following screenshot, you can see that the border is added around sections and that the gap between the columns is also minimized:

Another drastic change is the new Unified Interface design for Dynamics 365 apps, which gives the same user experience across various devices. Microsoft has already announced that from September 2019, the legacy web client will be deprecated. All customers need to move to Unified Interface before October 1, 2020.