You don't use the definite article when talking about companies/brands. However, you do use it when talking about products, because in those instances, you're using the brand name as an adjective. If you're talking about "the Huawei phone", the noun is "phone", so it follows the normal rules of grammar. The only difference is that you're using the company name as a modifier, but this doesn't affect the grammar.

Apple products are a bit different, because they often are the nouns themselves. You don't need to say "the iPhone phone". However, I would argue that the "i" in this instance is the modifier. Apple often uses the noun in the name of the item itself. A clearer example is "Apple Watch", where the brand name is clearly the modifier, and "Watch" is the noun. This is just a marketing strategy, but again, it doesn't affect the grammar.

Which watch is it? It's the Apple Watch.

Which phone is it? It's the iPhone.

@Abdullah

Thank you for the input.

I am wondering why the is necessary in 1) and not in 2)...

1) "The α6100 ensures you'll never miss an instant."

<a href="https://www.sony.com/electronics/interchangeable-lens-cameras/ilce-6100" rel="noopener noreferrer" target="_blank" style="color: rgb(241, 110, 81);">https://www.sony.com/electronics/interchangeable-lens-cameras/ilce-6100</a>;

<a href="https://www.microsoft.com/en-us/p/surface-book-3/8XBW9G3Z71F1?icid=PC_CP1_surface-book-3_4302020" rel="noopener noreferrer" target="_blank">https://www.microsoft.com/en-us/p/surface-book-3/8XBW9G3Z71F1?icid=PC_CP1_surface-book-3_4302020</a>;

Absolutely =} ... why else would I have posted it?

@človek

Are you aware that I posted the question on the link, right? I posted this question here because I wanted to explore more about the topic after reading the replies, so yeah...

@Gregory

When you say "the iPhone comes with a great camera." you mean all the series in general, right? I have this type of expression before but I was told that a product name is a proper noun, so it was not necessary to put "the" before the word...

but on this following page

"PlayStation" does not have "the"

"The ultimate home entertainment center starts with PlayStation™. Whether you’re into gaming, HD movies, television, music, or all of the above, PlayStation™ offers something great for everyone."

In the case of a model name, "the" is necessary, right?

<a href="https://www.sony.com/electronics/truly-wireless/wf-xb700" rel="noopener noreferrer" target="_blank">https://www.sony.com/electronics/truly-wireless/wf-xb700</a>;