This arrangement features teasel and sea-lavender. Teasel is translated into Katakana and is called chiizeru (チーゼル) in Japanese. Sea-lavender is called sutāchisu (スターチス), which is that Katakana version of another name for the flower in English, “statice.”
This is a jiyūka style arrangement, one way to tell the difference between jiyūka and seika is that seika arrangements usually feature only one type of flower.
When taking the photograph for this post, I noticed that on the camera screen the flowers looked bright blue instead of purple. Other people who took photos on their cellphones and cameras reported the same problem. Fortunately the photograph ended up being the correct color after moving it to my computer, but it sounds like purple can be a difficult color to capture on some cameras!