As far as I could find, I could not find a way to place the image on the x-axis. It is possible to place an image on the scatter points with the following code, which erases the ticks on the x-axis but should show them on your graph.
import plotly.express as px
import base64
x=[0, 1, 2, 3, 4]
y=[2, 1, 4, 9, 16]
fig = px.scatter(x=x, y=y)
team_logos = ['arizona_cardinals.png','atlanta_falcons.png','carolina_panthers.png','chicago_bears.png','dallas_cowboys.png']
fig.update_xaxes(tickvals=['','','','',''])
fig.update_layout(yaxis_range=[0,20])
# add images
for i,src,yy in zip(range(len(team_logos)),team_logos,y):
logo = base64.b64encode(open('./data/'+src, 'rb').read())
fig.add_layout_image(
source='data:image/png;base64,{}'.format(logo.decode()),
xref="x",
yref="y",
x=i,
y=yy,
xanchor="center",
yanchor="bottom",
sizex=3,
sizey=3,
)
fig.show()