More cute, chibi-filled, comedy entertainment with everyone's favorite, lazy, hamster hood wearing girl. It's more of the random, episode based comedy that you got in season 1 with most episodes split into 2 different short stories. There are some major changes though, in some ways they add more to the anime, but it comes at a price as well.
The theme this season is "friendship". There is a lot more screen time and inclusion on the other primary cast members such as Kirie and Nana for example. You get more background on Nana, and Kirie's brother is more frequently involved. Activities are done more on a group basis now, which is a good thing and adds character and relation to the Anime in the form of more meaningful content. You don't see characters alone as much, especially Umaru.
Since Umaru isn't seen alone as often anymore, you know what that means about her chibi, hamster hood phase. The price to pay for that meaningful bonding and focus on friendship means far less screen time of Umaru being in her lazy chibi form. This might be a positive thing for people who aren't quite as into that portion of the Anime, but it might be a slight disappointment for those who do enjoy it, as it was a signature concept of season 1.
The last change is the addition of new characters. There are a few new characters, you'll have to find out who they are yourself. They don't seem to add a whole lot, and are so-so additions. One character made sense due to them a family member, but even then, they just felt a bit forced as additions, and the screen time would have been better spent on Umaru and the others. Something that really stayed with me and ruined one of them, was their really bushy eyebrows, it detracted from them being a cute addition and made the character look and feel awkward, considering this was a feature that stood out.
The coolest feature this season has to be the opening and ending. Both have custom made lyrics for the anime and the lyrics custom voiced by the actors from the sounds of it. They are also rather catchy.
Overall it's what you'd expect based on season 1. You get more of all of that, but with a lot more focus on friendship. The screen time across characters is more balanced, at the cost of less Umaru chibi form. It's still cute, fun, and uplifting though, great for an evening to have some laughs, just not quite as good as season 1 due to less chibi Umaru mode (personal taste)
People giving this anime bad reviews because Umaru is a bratty character are totally missing the point. THAT'S WHY THE SHOW IS FUNNY, without her being the way she is - there is no split personality, there is no jokes and there is no show.
And oh boy, what a character she is! Love her or hate her, there is no denying she will leave an impression on you and you will never forget her cute little chibbi face and voice. She may actually be one of the most memorable (and cutest!) characters ever made in anime.
And btw, despite her egocentric character, she DOES care a lot about her friends and loves her brother more than anything.