The interior tab lets you buy furniture and decorative elements for the interior of your cafés, as well as increase its length or width. Interior items affect the prestige level of your café, which in turn determines the tips your staff members get when serving customers. Fernando can tell you what your tip level is at any time.
You can switch style at any time, or mix them as you wish although Fernando suggests you stick to one style for better tips. Each style has several "variations" which unlock as you level up. The more expensive the interior item is, the more prestigious your café gets. Mixing items from the same style has no adverse effect.
Café expansions are unlocked at level 5. Special styles (French, English, etc.) are unlocked at level 7.
List of styles
Click/tap for details.