Thermal compound for the mobile phone?

Since my display was broken, I disassembled my phone (HUawei P9) and ordered a new display. Now that all the parts were apart, I found that different chips were connected to some kind of thermal paste (or not?) To the metal module of the display. However, there's no thermal compound on my replacement display.

Now to my question: Should I use "normal" thermal paste, as they are used for the computer, omit them or make something else on it (maybe thermal pads)?

Did someone ever have similar experiences and / or know some advice?

Many thanks in advance!

At that time, I took some thermal grease for PC's on my Nokia 6, the smartphone is still working today!

Also makes no difference whether PC or mobile phone.

Do smartphones really need thermal grease? You are not getting hot at all? This is new to me I would be happy for a word.

If you play PUBG mobile now, for example, it can get warmer, but not as hot as a computer.