The style of her music videos range from girly, high tech, graphic and modern/ historical but they all follow a common structure of being over the top with everything. For example, in 'I Kissed A Girl' she is represented as likes to party and girly whereas in 'Unconditionally' she is mystical and fantasy-like. It is obvious that as she got more fame and power her budget for her music videos also go up. In 'I Kissed A Girl' the costume and sets are quite simple and can be achieved with average budget. However with one of her later videos like 'Roar' a lot more costume/makeup changing, extreme set ups and special effects has gone into it.
In terms of music, she started with her real name 'Katy Hudson' and created an album under that name with the genre Christian rock, contemporary. This album was created under the agency Red Hill Records. It was given positive ratings from professionals such as Billboard and AllMusic. However this album was not very successful as not much people know about it although it was given positive ratings and at this point she wasn't popular at all.
This album was a huge contrast to ones she makes now in terms of music style, the 'image', everything. She gained her fame after changing her album releasing company to Capitol Music Group which changed her whole image to a strong, independent women - a total contrast to the weak, inspiring girl with Red Hill Records. She started out with the album 'One of the Boys' in 2008 which made it to the top pop/rock songs on the chart.
As you can see from the album covers, there was a huge difference. There was much more budget invested in the later albums - much more photoshopping, a set up theme and even her image like her make up and hair has changed. The make up and hair is much bolder which connotes the 'strong' image the company tries to create. She also wear more revealing and bold coloured clothes to stand out and fit into her 'sex symbol' and 'men fantasy' roles that was ascribed to her by the public. Her styling also developed future with the help from the best hair stylist, make up artist, and costume artist as she got more well known.
These behind the scenes videos show how much the 'team' has planned for her image and how to express her in a positive way that the public will accept but yet find interesting. What she says is also planned to make sure she keep her image. They also try make her as innocent and nice as possible to avoid the public disagreeing and starts hating her.
It's hard to keep the stars on the front page all the time so they are always talked about somewhat positively. This is why the media sometime make up stories or make a certain situation bigger to be on the tabloids. For example, the recent story about how Katy Perry thinks that Taylor Swift's new song 'Bad Blood' is about her and the jealousy between the two with Harry Styles from One Direction. These are all from the star's team promoting their star by creating the word of mouth. Sometimes they might even give 'stories' to paparazzi so they can be on the tabloids and be gossiped about.