The peculiar bridge

Hi. I’m trying to improve my English.
I tried to describe the photo, though my description was terrible. … rence.html
Suppose I didn’t read the title or I didn’t know the Ponte Vecchio bridge.
This is a photo of a riverside landscape. There is a bridge across the river.
The bridge has a peculiar appearance. There are buildings on the bridge, and on all
along the bridge, there might be a corridor with roofs and walls. That might mean the bridge has the two-story structure, basically. The additional buildings on the bridge have two or three stories. The height of the corridor is four-story high.
The color of some buildings is yellow, and others are reddish. The corridor has creamy yellow walls.

At the bank of the river, there is a road, paved with stones. This is not asphalt paving or concrete paving, which makes me think that this city has a long history, and might be one of the European cities.
There are five motorbikes, one bicycle and a car running on the road.
All vehicles are coming toward the left direction. So it might be one-way traffic.
There is the barrier made of steel bars, which separates the motorway and the pedestrian walkway. I think the right sided road is the pedestrian walkway, not the motorway of the opposite traffic, because the width of it is relatively small. And if I look at the photo carefully, I can see that white striped lines which mean “a pedestrian crossing” is not extended on the right sided road. The lines are painted just on the left side. From that point of view, I’ve concluded the road at the right side is the pedestrian walkway. There is also another pedestrian walkway at the opposite side of the motorway, just next to the river.
Surprisingly, there is a house building even on the road. Of course it is a tall building which has two tunnels for motorcars and pedestrians.

The weather is cloudy. It might be winter. To say the least, it is not summer, because people are heavily dressed.

I wonder if you could correct my grammatical errors, and vocabulary or idiomatic errors.

I would like to ask two more questions.
In this situation, in which you and I am looking at the same photo, may I use only definite articles to indicate, for example, the (a) bridge, because you and I have the same bridge, as if you and I are looking at the same bridge in person, side by side.

And which do you recommend to describe what is/was in the photo, present tense or past tense?
I wonder that past tense might be better, because the photo was taken in the past.

Thank you for reading this.

You haven’t used only definite articles, but your usage is perfectly correct:

In general though, once the bridge has been introduced into the conversation, it will become ‘the’ bridge (unless there is also a second bridge).

The photo may have been taken in the past but you are looking at it in the present time. Either is fine. My choice would probably depend on how long ago the photo was taken and whether the scene is likely to have changed in the meantime.

Thank you, Beeesneees.
I got it. As an introduction, I should use “a”.

I got clear about tenses too. Your explanation makes sense.
After I’ve heard it from you, it seems a matter of course. Why did I know it in advance?
If I describe a photo which seems to have been taken in 1900’s, I too will describe it in the past tense, naturally.