A word for the smaller side? For a laptop, if you say that the USB port is on the side, you can easily understand, but if it's a rectangular prism, it's harder to understand which side you're talking about. Is there a word for the smaller side in English?
When you say the 'shorter' sides of a laptop, I presume you are referring to the fact that a rectangle has two shorter parallel sides and two long sides.
There are no specific names in geometry to distinguish between the longer sides and shorter sides of a rectangle, but that isn't a problem in the case of an object like a laptop.
It would be assumed that any user would be looking at it from the same angle, so you could refer to the edges in relation to the orientation of the machine - the front, the back (or rear), the left side and the right side. For example, on my laptop, there are two USB ports on the left side, and two on the right. There is a card reader on the front. The power socket and RGB ports are on the back.
You could even say "turn the laptop around so you are looking at the back of it". When something is intended to face a certain way, it doesn't matter where it is in relation to you - its back is always its back.
The 'sides' of a 2-dimensional shape are not the same as the sides of a 3-dimensional shape like a laptop anyway. What you are referring to may well be called a 'side' but it could also be called the 'edge'. As a laptop is unlikely to be a strict 3-dimensional geometric shape with perfectly flat 'faces', nobody in everyday speech would use the term 'face' like they might with a box.
A rectangular prism has six rectangular sides, in three pairs of equal area. There are names for the sides relative to the person, and the ground:
Top, bottom, Left, right
Now obviously for a simple prism, the left for one person might be the right for another. So you might hear "my left" or "your left".
There is no special word for "one of the small faces" but you could use exactly that phrase
one of the small faces.
Talking about prisms is rare outside of maths lessons. But this also applies to things like boxes.